# UVB exposure Dendrobates



## Ed

First part 

https://aark.portal.isis.org/researchguide/amphibian%20zoo%20studies/amphibian%20uv-b%20and%20vitamin%20d3.pdf


UV-B, Vitamin D3, and amphibian health and behaviour
Dr Robert Browne, Postdoctoral Fellow, [email protected]; and Dr. Francis Vercammen, Veterinary Officer,
Center for Research and Conservation, Royal Zoological Society of Antwerp, Belgium.
Elfi Verschooren, University of Antwerp, Belgium.
Rachael E. Antwis, Faculty of Life Sciences, University of Manchester, UK.
We thank Richard Gibson, Chester Zoo, for his personal contribution on “UV-B boost”.
Browne RK, Verschooren E, Antwis RE, Vercaammen F. 2009. UV-B, Vitamin D3. AArk Science and Research.

http://portal.isis.org/partners/AARK/ResearchGuide/Amphibian%20zoo%20studies/Amphibian%20UVB%http://portal.isis.org/partners/AAR... zoo studies/Amphibian UVB and Vitamin D3.pdfhttp://portal.isis.org/partners/AAR... zoo studies/Amphibian UVB and Vitamin D3.pdfhttp://portal.isis.org/partners/AAR... zoo studies/Amphibian UVB and Vitamin D3.pdfhttp://portal.isis.org/partners/AAR... zoo studies/Amphibian UVB and Vitamin D3.pdfhttp://portal.isis.org/partners/AAR... zoo studies/Amphibian UVB and Vitamin D3.pdfhttp://portal.isis.org/partners/AAR... zoo studies/Amphibian UVB and Vitamin D3.pdfhttp://portal.isis.org/partners/AAR... zoo studies/Amphibian UVB and Vitamin D3.pdfhttp://portal.isis.org/partners/AAR... zoo studies/Amphibian UVB and Vitamin D3.pdf20and%20Vitamin%20D3.pdf​

For a review of the biology of Vitamin D3 and UV-B metabolism in amphibians see; Antwis RE, Browne RK. 2009.
Ultraviolet radiation and Vitamin D3 in Amphibian Health, Behaviour, Diet and Conservation. Comparative
Biochemistry and Physiology Part A154(2): 184-190.


……………………………………………………………………………………………………………………………………​
This document provides a short summary of the biological issues concerning studies of Vitamin D3 and UV-B metabolism in amphibians. We also present some simple experimental designs. There have been many effects on health of vertebrates in general attributed to poor Vitamin D3 metabolism. However, only two effects have been recorded in amphibians. One is the loss of calcium from the skeleton and skeletal deformaties generically called nutritional metabolic bone disease (NMBD).
The other, being the converse situation, is an overdose of Vitamin D3 and the consequent elevated plasma calcium levels that cause excessive calcification of the skeleton and heart siezure. Generally in captivity a lack of dietary calcium or Vitamin D3 is attributed to the common disorders of hunchback or rubbery legs. Often frogs not showing skeletal deformaties will still have little calcium in their bones, and perhaps reduced circulating calcium necessary for physiological processes.

There have been many effects on health of vertebrates in general attributed to poor Vitamin D3 metabolism. However, only two effects have been recorded in amphibians. One is the loss of calcium from the skeleton and skeletal deformaties generically called nutritional metabolic bone disease (NMBD). The other, being the converse situation, an overdose of Vitamin D3 and consequent elevated plasma calcium levels that causes calcification of the skeleton, increased myocardial excitability and heart seizure. In captivity generally a lack of dietary calcium or Vitamin D3 is attributed to the common disorders of hunchback or rubbery legs. Often frogs not showing skeletal deformaties will still have little calcium in their bones, and perhaps in their plasma. Approximately 20% calcium loss in bones can be detected on
radiographs and a loss of 35% can lead to rubbery legs. A shortage of calcium in amphibian metabolism results in lack of calcification of the bones – called nutritional metabolic bone disease (NMBD), and other health problems including lethargy, poor growth,and possibly poor reproductive success. Both anabolism and catabolism are involved in Vitamin D3 metabolism. Vitamin D3 is required for the transport of calcium from the intestine into the blood stream. Vitamin D3 can be acquired through the diet or by synthesis in the skin under the influence of UV-B. UV radiation is emitted by the sun as wavelengths ranging from 400 nanometres (nm) to 100 nm.


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## Ed

Part 2

This range is further subdivided into the sub-categories of UV-A (400–315 nm), UV-B (315–280 nm) and UV-C (280–100 nm). Only UV-A and UV-B solar radiation can naturally interact with biological systems, as wavelengths shorter than 290 nm are completely absorbed by the Earth's atmosphere (Antwis and Brown 2009).

Phosphorus is also an important component of bones and must also be included with calcium in the diet.Consequently, amphibians must have adequate calcium and phosphorus in their diet, and sufficient Vitamin D3 must be supplied through the diet or by UV-B lights. For a discussion of the provision of dietary calcium and phosphorus see (Amphibian diet and nutrition).

Studies have shown that Dendrobatid species behaviourally regulate their exposure to UV-B; some aquatic amphibians can detect UV-B through their eyes (Deutschlander and Phillips 1995; La Touche and Kimeldorf 1979), and the ability to detect near UV-B radiation of 280 nm has been shown in frogs eyes Govardovskii and Zueva 1974). More knowledge about UV-B behavioural regulation would enable more leeway in the optimal provision of UV-B in captivity, and may have consequences for amphibianconservation in nature.​UV-B can be provided by several types of lights. Some of these produce large amounts of UV-B along with a large amount of heat. These are often used for reptile. However, fluorescent lamps that run fairly cool are preferred for amphibians because of their generally low UV-B and temperature requirements. For information on the best lights to use see http://www.uvguide.co.uk/Vitamin D3 can be provided orally in feed, through supplemented live feed (crickets)(Li et al. 2009),through dietary supplementation of live feed (Li et al. 2009; bioteck.org 2009), through mixtures used
directly for forced feeding, and as drops to the mouth (see Amphibian diet and nutrition). Vitamin D3 can also be provided topically through the skin. Vitamin D3 is fat soluble and in drops must be in a carrier like propylene glycol. Until further studies are completed for frogs we recommend a daily dose of 330 IU
Vitamin D3 per. kg per day given orally through drops. We consider it too difficult to give drops orally to very small frogs below 5 g, and even a measurable dose topically to frogs below 1.5 g.

Amphibians vary very highly in their exposure to UV-B. Amphibians include nocturnal, fossorial, or aquatic species with large variations in UV-B exposure. These vary from almost no exposure for fossorial amphibians or those that live in water more than 10 cm deep, to very high amounts for species that sun bask in during summer in temperate or tropical regions. The requirement for metabolic Vitamin D3 and the ability of UV-B to promote the production of Vitamin D3 in amphibians probably positively corresponds to their exposure to UV-B. Consequently, some species may have very low or no requirement for UV-B and low requirements for Vitamin D3 from their diet. Others may have very high requirements. Knowing the patters and the amounts in the requirement for Vitamin D3 and UV-B exposure between species from similar micro-habitats could help prevent hypervitaminosos.

However, even though we know that some species develop NMBD in captivity, even when fed crickets dusted with vitamin/mineral powder, there have been no formal studies to assess the needs of amphibians for UV-B and Vitamin D3. To avoid the need for the use of continuous UV-B lighting some zoos including Chester Zoo (North of England Zoological Society) and Rotterdam Zoo, Netherlands, have used boost application of UV-B on Dendrobatid frogs. This consists of high levels of UV-B for short
periods of 20 minutes monthly. Vitamin D3 can be stored in the liver and with mammals has a half life of about two weeks.


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## Ed

“The 'UV-B boost method was developed at Chester Zoo, UK, by Douglas Sherriff and Edwin Blake. Frogs are placed in an enclosure with a screen mesh lid that guarantees exposure of the frog to UV-B. A damp paper towel and cool room temperature reduce the chance of dehydration and overheating. If necessary lateral ventilation panels in the tank and a cooling fan can be used. This enclosure is placed beneath a UVB-emitting lamp – either an Osram Ultravitalux or a Zoologist Megaray – at a distance to directly achieve a UV-B level of 350-400 μw/cm2.
A finer mesh cover for very small frogs including (_Ranitomeya reticulatus _and _R.lamasi_) results in a reduction of UV-B exposure to about 30μw/cm2. Frogs are ‘boosted’ monthly for 20 min. Observation of the frogs throughout the boost and use of a timer is important to avoid problems with over-exposure. For example, a group of _R.reticulatus _was inadvertently boosted for 45 min. This resulted in superficial discolouration of the skin that healed within a fortnight. These frogs then went on to reproduce successfully (Gibson pers. com.).”

Studies of UV-B/Vitamin D3 and amphibian health offer an ideal research focus for zoos, as very little is known about this subject that is so important to conservation breeding programs and the welfare of amphibians in captivity. Zoos, privates and other institutions can through pioneering studies of UV-B and Vitamin D3 improve the health of captive amphibians, and provide basic knowledge to support the ecology and physiology of amphibians in nature. Studies of UV-B/Vitamin D3 will also encourage studies of other nutrients and micro-nutrients. Studies design for studies of larval and adult amphibians. We use plastic boxes (41 cm L x 34 cm W x 17 cm H) with a hole cut in the lid and covered with 1 x 1 cm x 1.7 mm plastic garden mesh. The bottom of the box is covered with paper towel and an 18 cm diameterx 2 cm depth water bowl provided. Paper towel was changed every two days and water replaced daily or with soiling. Lighting is provided by fluorescent lamps suspended over the mesh. For UV-B treatments strip lights are Zoo Med Reptisun 5.0 UVB (14W, 375mm/15”) or Zoo Med Reptisun 10.0 UVB (15W,475mm/18”). An aluminum hood increases UV-B levels by 40%. UV-B levels were measured with a Zoo Med ST-6 Digital Ultraviolet Radiometer (range 280-325 nm, peak 290 nm, accuracy ± 10%). UV-B levels for Reptisun 5.0 in the box vary from 9-24 and with the Reptisun 10.0 from 23-50 μw cm-2.Few studies have examined the behavioural sensitivity of adult amphibians to U-B radiation; however, Han et al. (2007) found UV-B avoidance behaviour in two Neotropical poison-dart frogs. Using a simple enclosure that provides UV-B or equivalent light without UV-B, and a web cam with a time lapse imaging system, researchers can with minimal effort reliably test UV-B avoidance behaviour in wide range of frog species. If the study is investigating behaviour the box can be partitioned with a vertical barrier, with a UV-B fluorescent tube either side, with Mylar blocking the UV-B on one side (Han et al. 2007). Responses in UV-B/Vitamin D3 studies include x-rays, weight and length, skin colouration and condition,and Vitamin D3 levels. The inability to assay Vitamin D3 levels except for plasma or whole body are restrictive. Blood can only be taken from larger amphibians In ectotherms, about 50% of the blood can be removed at one time. This is roughly 5% of the body mass. The smallest amphibian from which 0.2 ml whole blood needed for many assays can be sampled is 4 grams, and from which 0.5 ml whole blood can be removed weighs 10 grams (NWHC 2009). Tests for Vitamin D3 (calcitriol) using radio imumo-assay require on drop of blood.

_Above: A highly adapatable and robust habitat for testing UV__‐B is a plastic box with a hole cut in __the lid and plastic garden mesh covering. A fluorescent light can be placed over the top of the __mesh and then covered with analuminium foil cover. The aluminium cover reduces dispersion of __the light and increase UV__‐V in the box by 40%._​_Left: Groups of many replicates can also be housed in similar __arrangements. Juveniles of species that are sun baskers __including Amazonian milk frogs (Trachycephalus __resinifictrix)are easy to keep on a foam mat in a water bath in __plastic containers with curtain mesh on top. This technique __enables the housing of many replicates in a small area. _

Amphibians physiologies and their needs for UV-B and Vitamin D3 possibly vary dependent on their natural UV-B exposure. At Antwerp Zoo for research we are categorising anurans as receiving high, medium and low UV-B exposure in natuire. Green and Golden bell frogs (_Litoria aurea_), and some African reed frogs (_Hyperolius _spp.), that sunbask in the hot summer are considered high UV-B species. Amazonian milk frogs(_Trachycephalus resinifictrix_) males call from tree hollows but move during the day toward the canopy. The metamorph frogs have been observed to prefer exposure on foliage in captivity. They are related to the poison dart frogs and also produce a milky secretion that is probably discouraging to predators. Consequently, we regard _T_. _resinifictrix _as a medium UV-B requirement species in respect to natural UV-B exposure. Low UV-B exposure species are those that are crepuscular including tomato frogs (_Dyscophus antongilii_). How these categories relate to UV-B and Vitamin D3 needs, and to behavour in respect to UV-B levels, are the subject of ongoing studies. _Right: Portable x-ray machines enable x-rays of very high resolution. __This x-ray shows the early skeletal development of a tail bud T. __resinifictrix only about 14 mm in snout-urostyle length_


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## Dangerously

Who can summarize this one one short paragraph, and lay out some recommendations in another?


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## hypostatic

I think the main summary is that your frogs need vitamin D3, so that they can metabolize calcium properly. Many anurans (people too!) use UV-B radiation from the sun to synthesize vitamin D3, but in captivity many anurans don't receive the UV-B that they normally would, so supplementation of vitamin D3 to their diet is essential to their development. The article goes on to say that zoos have tested adding UV-B to frogs and found out that many frogs can behaviorally regulate their UV-B intake (some can detect UV-B with their eyes). The article also stated that "Han et al. (2007) found UV-B avoidance behaviour in two Neotropical poison-dart frogs."

Reading this article makes me think about how member Mworks stated that he supplements his histrionicus with UV-B lighting (monthly I think), and that they come out from hiding and "sunbathe" when he does so.


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## mordoria

So, is it my understanding, that I could possibly overdose my frogs with D3 by supplementing D3, and using UVB light? It seems they did it with a Ranitomeya reticulatus and R.lamasi and it caused a "sunburn" of sorts, which healed shortly. 
Should we "dose" our frogs with some uvb? I know some users like STU&SHAZ have adapted their system to use UVB lighting. 

ED, Do you have any UVB tests under your belt? Conclusions?


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## Ed

The formation of D3 is controlled by feedback mechanism.. if there is sufficient D3 in the animal, further conversion of D3 will not occur so there isn't a risk of overdose by supplying access to UVB as well as supplementing the frogs. Overdosing of D3 is pretty much restricted to the oral ingestion of vitamin D3. 

There is data slowly emerging from other taxa (including those typically considered to not need additional D3 (snakes), that if given the opportunity they will behaviorally maintain a higher circulating level of D3. 

For some discussion on these topics see http://www.solarmeter.com/pdfs/paper2.pdf 

AVMA - American Journal of Veterinary Research - 69(2):294 - Abstract (not a free copy)

There is some evidence that allowing the frogs to behaviorally modify exposure to be of benefit to the frogs. This means that more thought has to occur in planning as the frogs are known to avoid (if possible) excess exposure including choosing calling perches that are not exposed to UVB. See http://people.oregonstate.edu/~blaustea/pdfs/HanBiotropica2007.pdf

Ed


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## stu&shaz

Once again Ed thankyou for posting. You have just prempted a post by us about this very subject.Do you have any information on anystudies or on how the use of uvb lighting might be of benefit to tadpols and helping with sucessful morphout,ie prevention of sls.?
We are just experimenting with one of the new arcadia T5 24watt D3 6% over our tad rearing set up. Arcadia seem to have done alot of reserch into this product,from my limited knowledge it seems to be the best option available for our dartfrogs,but i personnally would like a lower wattage option, in some tanks we only use 14watt. As above we also utilise T5 bio vital bulbs over our vivs.
We have taken the pragmatic view of using different types of glass (ie low iron) to give differing levels so the frogs can self regulate,in viv. With the tadpols we are giving a good piece of oakleaf for potential shade,again for self regulation.Deep thought is given, as best we beginners can, to our frogs in viv being able to use the uvb and behave normally in areas of the tank that are shaded from it aswell.
Our leanings towards this were 2 fold,1 mworks posts and 2 obseving our auratus "sunbathing" in a shaft of sunlight early mornings standing high legged,i would hasten to add we moitored temperatures very carefully during this very brief early morning period,with concearn about viv temperatures rising excessively,but all is well. When our room is eventually finished we will be running a 2 fold lighting system uvb bulbs in the center of the day and an led system on throughout the day...any thoughts?
Paramount in all this is the thought of self regulation by our charges
regards
Stu


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## Ed

based on the huge amount of data out there I would not use UVB for tadpoles.. there is some good data out there that tadpoles may not avoid damaging levels of UVB 

See for example Larval amphibians seek warm temperatures and do not avoid harmful UVB radiation 

It also makes the tadpoles less tolerant of poor water conditions (see for example http://people.oregonstate.edu/~blaustea/pdfs/Macias_et_al_STOTEN_07.pdf

for a more generalized discussion see 
http://www.uoguelph.ca/~salex/Can. J. Zool. 77.1956.1966 (1999).pdf 


Ed


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## Mworks

Like Ed I believe that providing UVb for tads may not only be unnecessary but may be potentially damaging to tadpole development. When providing the histrionica with a UVb session I noticed a visible tad in one of the brom axils would 'go deep' when the bulb was switched on. Finding another tad in the BriBri viv I tried with the UVb directed on it's axil - similarly the tad 'went deep'.
This happened several times so my conclusions were that the tad knew what it needed and UVb wasn't on it's list. 

Since that incident I have never thought of providing UVb for my tads. I also notice that many now provide constant UVb for their frogs. As I have mentioned previously I decided not to do this as after about 30 mins 'sunbathing' under a 10% Arcadia bulb every frog I have leaves the 'UVb lit' area and re emerge when the bulb is switched off. 

I have also started to open the doors on some of the vivs with frogs I trust won't jump out. Of course I sit with the lamp ensuring no escapes and I have noticed that the frogs seem to have an awareness of UVb strength as they 'bathe' about 3 inches farther back than when the doors are closed and the UVb is going through the Optiwhite glass I use on all my viv doors. Coincidence - I don't know yet - I should have a better idea after a few more months experimenting.

Regards
Graham


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## stu&shaz

Ed said:


> based on the huge amount of data out there I would not use UVB for tadpoles.. there is some good data out there that tadpoles may not avoid damaging levels of UVB
> 
> See for example Larval amphibians seek warm temperatures and do not avoid harmful UVB radiation
> 
> It also makes the tadpoles less tolerant of poor water conditions (see for example http://people.oregonstate.edu/~blaustea/pdfs/Macias_et_al_STOTEN_07.pdf
> 
> for a more generalized discussion see
> http://www.uoguelph.ca/~salex/Can. J. Zool. 77.1956.1966 (1999).pdf
> 
> 
> Ed


thanks Ed for the links i will come back when i have dijested them fully...shattered again thenkyou for your thoughts
regards
Stu


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## stu&shaz

Mworks said:


> Like Ed I believe that providing UVb for tads may not only be unnecessary but may be potentially damaging to tadpole development. When providing the histrionica with a UVb session I noticed a visible tad in one of the brom axils would 'go deep' when the bulb was switched on. Finding another tad in the BriBri viv I tried with the UVb directed on it's axil - similarly the tad 'went deep'.
> This happened several times so my conclusions were that the tad knew what it needed and UVb wasn't on it's list.
> 
> Since that incident I have never thought of providing UVb for my tads. I also notice that many now provide constant UVb for their frogs. As I have mentioned previously I decided not to do this as after about 30 mins 'sunbathing' under a 10% Arcadia bulb every frog I have leaves the 'UVb lit' area and re emerge when the bulb is switched off.
> 
> I have also started to open the doors on some of the vivs with frogs I trust won't jump out. Of course I sit with the lamp ensuring no escapes and I have noticed that the frogs seem to have an awareness of UVb strength as they 'bathe' about 3 inches farther back than when the doors are closed and the UVb is going through the Optiwhite glass I use on all my viv doors. Coincidence - I don't know yet - I should have a better idea after a few more months experimenting.
> 
> Regards
> Graham


Again Graham thankyou for your thoughts,as with Ed your wisdom is greatly valued,i thought that the low levels available to our frogs as overhead,might be a way of self regulation,its is only the back 15cm or so of our vivs top,that actually uses low iron/optiwhite glass,in all vivs i think this area of background is heavily planted,and lower levels in full shade so a frog would have to actively seek said light,the majority of the viv top is constructed ofnormal 4mm which i thought only let very low levels of uvb through, which i didn't think would be of any potential risk to our frogs,coupled with the uvb lighting only being on for the middle part of the day i believed,i had a system figured that would let them chose and not be reliant on me,chosing for them.
As regards the tadpols interesting observations,i might have to change things,i need to read through Ed's links,which you both know how i struggle with thses scientific data type posts so will need to be of a clearer head to assimalate something from them,that is if I can understand them at all,as before i don't think i see letters quite the same as other folks do. I based my initial thoughts for using this with them, on factors such as low strength bulbs,poor penitration of rays into water.But of course my simple laymans/stockmans logic,not that of the more scientic data that you guys are able to access ,but for me is next to impossible to read,i deeply struggle with the english,always have always will.I have also read that uvb could be beneficial in combatting fungal infections and help with water quality.
With our 14 watt bulb we have so far encountered no visable problems,but it is very early for us,in less than a week i guess 3 more tads will morph all look ok i think,but its just so early for me/us yet,first season and all, its utterly impossible to be sure of anything we are doing .
Thanks again buddy and to Ed
regards
Stu


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## Ed

Actually if you dig around in the literature, there are a number of papers that indicate increased susceptiability to fungal infections for tadpoles exposed to UVB light. We should keep in mind that most of the dendrobatid tadpoles are not going to be found in locations that are going to have significant UVB exposure. (leaf axils (shaded by other leaves/tissues, small pools or puddles under the canopy are two off the top of my head) so they are probably going to be very sensitive to UVB. 

The whole idea for UVB usage for tadpoles was due to a practice in a European Zoo that was published in the old British Dendrobatid Group News letter. It used to be available on the old BDG website, but since that went down, I haven't seen it around. It was done during the old days when there was a lot of voodoo guesswork on how to prevent spindly leg syndrome in tadpoles. It hasn't been supported by the literature as a good practice and we have a much better handle on spindly leg now due to some recent studies. 


Ed


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## stu&shaz

Ed said:


> Actually if you dig around in the literature, there are a number of papers that indicate increased susceptiability to fungal infections for tadpoles exposed to UVB light. We should keep in mind that most of the dendrobatid tadpoles are not going to be found in locations that are going to have significant UVB exposure. (leaf axils (shaded by other leaves/tissues, small pools or puddles under the canopy are two off the top of my head) so they are probably going to be very sensitive to UVB.
> 
> The whole idea for UVB usage for tadpoles was due to a practice in a European Zoo that was published in the old British Dendrobatid Group News letter. It used to be available on the old BDG website, but since that went down, I haven't seen it around. It was done during the old days when there was a lot of voodoo guesswork on how to prevent spindly leg syndrome in tadpoles. It hasn't been supported by the literature as a good practice and we have a much better handle on spindly leg now due to some recent studies.
> 
> 
> Ed


 Absolutly see your logic here Ed,of course i need to walk where our dartfrogs live observe,think evaluate and then put that into practice,that would be the way for my brain to work out how much light/not only uvb our frogs need,but i doubt this will happen so every conversation like this becomes hugely important. I wasn't actually aware of the thoughts by the BDS. But our use of uvb has been very much driven by the wish to not see sls,your last sentance becomes all important now because i deeply feel there is something on sls that i have totally missed out on,i'm also warey of asking more here on your thread because it wll take you thread totally leftfield i fear and into a disscussion on sls.
Ed i have had ago at the first two papers,laymans thoughts
1 my conclusion is that the tadpols will congragte in areas of water that is the right temperature for them,if that means too much uv this is not as important to them as the temperature...even if it harms them
2nd paper when testing for problems with pollution ie nitrate uvb can have an exagerating effect to the consequences of said polution,so needs to be factored into experiments.uvb can act as a "catylist" making environmental problems for phibs greater
have i got the gist of these studies?
Finally with regard to your last post,are there any studies any tables of which darts receive higher light levels which darts live in the darkest places...is there any correlation between different morphs of a species and light level?
This would give us a fairly simple laymans guide to how bright our viv should be,and how much uvb a given dart might need, well maybe.
i'm gonna have a go at that third paper now,wish me luck
thankyou
Stu
Ps i'm probably drawing the wrong conclusion here but do auratus live in real dark places...dense cover overhead,maybe moreso than tinctorius?


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## Ed

Have you read the link between spindly leg and vitamin A in the form of retinyl acetate/palmitate? In researching stuff up I located a paper that descibed deformations that occured when they blocked the metabolism of vitamin A and it matched the condition we call sls.. (and issues with fertility and tadpole development). 

Ed


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## stu&shaz

Ed said:


> Have you read the link between spindly leg and vitamin A in the form of retinyl acetate/palmitate? In researching stuff up I located a paper that descibed deformations that occured when they blocked the metabolism of vitamin A and it matched the condition we call sls.. (and issues with fertility and tadpole development).
> 
> Ed


No not yet,i was reading a long thread on here last night on sls,got to page 6 computer halted progress,i have become very aware of vit a from your posts,and that amphibians have difficulty assimalating this from their diet?,am aware that you have reversed poor hatches,with bimonthly vit a and contacted Allen for some thoughts too. At presant hatches are steadily improving (young frogs) tad viability good,and early morphout good so far aswell.Haven't used vit a (although some is on its way just in case) as don't yet feel any need to do so. All good so far,a bit bewildered by how well actually.
A link would be awsome,sorry for going off topic,but other guys like us i guess will be having similar thoughts and will learn too 
thanks again
regards
Stu


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## Mworks

Stu
I don't believe there is a 'quick fix' to any of this - nor should there be! The more we experiment with vits, lighting and viv environments the more benefits we will eventually pass on to our frogs - and that's what it's all about. The more we discover, digest and share the better this hobby becomes. So as far as I'm concerned you are doing it 100% right - see what works for you - document it and share your success and remember sharing things that don't work is just as important.

Regards
Graham


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## stu&shaz

Ha mate i SO agree with every word of that !! And have pretty much tried to share all that i learn as i go and the thought behind it,sometime uninformed decissions lead to break thoughs...sometime disaster,but we have to try as best we are able. But mate its so cool being able to have access to folks like yourself and Ed whom try to help us so much,yeah sometimes its hard going for me to understand but as you say i'm not after quick fixes stock is about thought obsevation and diligence,making choices and reacting fast when observation tells us too.
Yeah it his hard sometimes to tell folks when we get it wrong but it is so important that others learn from this aswell!! Thanks Graham
regards
Stu


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## Ed

stu&shaz said:


> No not yet,i was reading a long thread on here last night on sls,got to page 6 computer halted progress,i have become very aware of vit a from your posts,and that amphibians have difficulty assimalating this from their diet?,am aware that you have reversed poor hatches,with bimonthly vit a and contacted Allen for some thoughts too. At presant hatches are steadily improving (young frogs) tad viability good,and early morphout good so far aswell.Haven't used vit a (although some is on its way just in case) as don't yet feel any need to do so. All good so far,a bit bewildered by how well actually.
> A link would be awsome,sorry for going off topic,but other guys like us i guess will be having similar thoughts and will learn too
> thanks again
> regards
> Stu


Unfortunately there isn't a free copy available of that article. See ingentaconnect Abnormalities of forelimb and pronephros in a direct developing f... 

I was researching further into the issues from insufficient vitamin A as we were working with some deficient Bufo baxteri and I had seen issues with egg clutches of several hylids when I had run across this citation.

Ed


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## jacobi

I cant afford a solarmeter at this time. Are there any approximate guidelines for which strength bulbs and distances to use, with a glass cover,? I am aware that glass does block UV, interestingly, I haven't actually found any studies of any kind that this is the case, merely hearsay and experience of others.


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## Ed

jacobi said:


> I cant afford a solarmeter at this time. Are there any approximate guidelines for which strength bulbs and distances to use, with a glass cover,? I am aware that glass does block UV, interestingly, I haven't actually found any studies of any kind that this is the case, merely hearsay and experience of others.


Evaluation of UVB reduction by materials commonly used in reptile husbandry - Michael Burger - 2007 - Zoo Biology - Wiley Online Library

http://www.guardian.com/stellentdev/groups/climaguard/documents/native/gi_004941.pdf 

Those were two of the studies that I found within a page or two of google scholar. 
Ed


----------



## jacobi

Thanks. I will need to expand my vocabulary when using scholar. I didn't use any variation of "transmitting" or "transparency". Dumb. Lesson learned.

Evaluation of UVB reduction by materials commonly used in reptile husbandry - Michael Burger - 2007 - Zoo Biology - Wiley Online Library requires a fee... I cant afford it. Bugger. The joys of college.

Now I feel stupid and poor 

Added it to the list of articles to read when I can...

And... I don't feel quite as stupid. There are many articles dealing with additives to glass that absorb/block UV, or UV blocking plastics, but very few that actually refer to or measure UV transparency, and those only mention it in passing. Looks like most researchers are interested in blocking UV. Not much interest in allowing it through, apart from flora/fauna related interests.
Interestingly, http://www.guardian.com/stellentdev/groups/climaguard/documents/native/gi_004941.pdf only provided manufacturers specs. Lots of information on glass, but no independent studies. Looks like "Evaluation of UVB reduction..." moves to the top of the reading list.


----------



## Julio

i am gonna start experimenting with this in some of my frogs, can you guys recomend a good fixture and bulb?


----------



## rsain

jacobi said:


> Evaluation of UVB reduction by materials commonly used in reptile husbandry - Michael Burger - 2007 - Zoo Biology - Wiley Online Library requires a fee... I cant afford it. Bugger. The joys of college.


Did you check for this through your university library system? They may already be paying for access to it - as a result you could access. I know that our university (a rather small one) provides access. You could also request an interlibrary loan for this article (probably free maybe 3 bucks for the copy). 

Go to your library page search for the Wiley Library database then find the Zoo Biology journal. 

Burger, M.R., Gehrmann, W.H., Ferguson, G.W. (2007). Evlauation of UVB reduction by materials commonly used in reptile husbandry. Zoo Biology, 26(5), 418-423. (volume 26 issue 5). 

If that proves unsuccessful pm me. 

- ryan


----------



## jacobi

rsain said:


> Did you check for this through your university library system? They may already be paying for access to it - as a result you could access. I know that our university (a rather small one) provides access. You could also request an interlibrary loan for this article (probably free maybe 3 bucks for the copy).
> 
> Go to your library page search for the Wiley Library database then find the Zoo Biology journal.
> 
> Burger, M.R., Gehrmann, W.H., Ferguson, G.W. (2007). Evlauation of UVB reduction by materials commonly used in reptile husbandry. Zoo Biology, 26(5), 418-423. (volume 26 issue 5).
> 
> If that proves unsuccessful pm me.
> 
> - ryan


I will definitely try that. Now that I think about it, I have barely touched the school's library system. They definitely have intersystem loans. I'm going to see what they have. Thanks for suggesting that. Its strange, I guess mostly because of the convenience of google, I don't think of using the library. I am going to change that now!


----------



## rsain

jacobi said:


> I will definitely try that. Now that I think about it, I have barely touched the school's library system. They definitely have intersystem loans. I'm going to see what they have. Thanks for suggesting that. Its strange, I guess mostly because of the convenience of google, I don't think of using the library. I am going to change that now!


Good answer!  

Keep in mind, your student fees pay for things like access to the journal in question and many many others. Our uni provides access to all sorts of things that many people don't know about but pay through the nose for (e.g., access to tons of high end software through remote desktop services).

- ryan


----------



## Mworks

Julio said:


> i am gonna start experimenting with this in some of my frogs, can you guys recomend a good fixture and bulb?


This is what I use......... not sure if IKEA is in the US.....................

As most of you know I put real importance on providing UVb for all my frogs. I made up a lamp a few years ago that did the job but was a bit of a pain to use - bring a chair to rest it on to light some of the viv.

So I decided that this week while it was half term that I would 'build' something more practical. We had been over to Ikea and Global light (£14) caught my eye as being perfect for adaption. It bends and twists in all directions and fastens to any shelf and all of my vivs are on some sort of shelf I thought I'd give it a go.

Here's the lamp before I 'adapted it.









Then using the Arcadia parts I already had

Lampholder









Reflector









and bulb D3+ 10%UVb









Then it was just a matter of removing the lamp fitting and rewiring in the Arcadia lampholder which fits really neatly on the swivel head that the Ikea lamp comes with.

Here's a close up of how the original wiring that is internal to the lamp fits the Arcadia lamp









and finaly a couple of shots of the new UVb set up in action - I am really pleased with it and it will make UVb day (once a week each viv gets one hour of UVB lighting) so much easier.

here it is on the Retic viv









and on the White Foot viv









It was just so easy to convert and looks like it has been manafactured by Arcadia - I should patent the idea!

Regards
Graham


----------



## Julio

Are u using reptisun 10.0 bulb?


----------



## mordoria

Is the glass on the front of the viv, a low iron glass? Or is that why you put the bulb so close?


----------



## Mworks

Julio said:


> Are u using reptisun 10.0 bulb?


Arcadia bulb D3+ 10%UVb


----------



## Mworks

mordoria said:


> Is the glass on the front of the viv, a low iron glass? Or is that why you put the bulb so close?


All the doors on my vivs are made from Opti white Glass (low iron) which allows UVb pass through.

Regards
Graham


----------



## Ed

Mworks said:


> I have noticed that the frogs seem to have an awareness of UVb strength as they 'bathe' about 3 inches farther back than when the doors are closed and the UVb is going through the Optiwhite glass I use on all my viv doors.


Not singling you out, just using this to illustrate some information that is circulating round the hobby.. 

Using O. pumilio as a model there isn't any indication that the frogs can actually see UVB (or UVA) light see http://core.ecu.edu/biol/summersk/s...ion in spectral reflectance in D. pumilio.pdf as they lack the structures in thier eyes to see into that frequency (specifically see


> There is little or no evidence that D. pumilio does have UV sensitive cones (E. Loew, pers comm.) which would allow these frogs to percieve reflectance in that region of the electromagnetic spectrum. Morever our measurements suggest that all the different morphs of D. pumilio have very little reflectance in the UV, implying that UV colours may not be important for social interactions in this species


We also know that the frogs avoid excess exposure to UVB see http://people.oregonstate.edu/~blaustea/pdfs/HanBiotropica2007.pdf .. which indicates that the frogs can detect UV exposure, but we aren't sure of the exact method but it is probable that it may at least depend on the circulating levels of vitamin D3... 

Some further comments,

Ed


----------



## suztor

Quick question. So do frogs require special lighting like reptiles(have I missed this in my reading)? Or is it an only occasional special lighting. Or do the powder supplements/dustings cover the need for it?


----------



## rsain

In short (someone correct me if i'm wrong):

Frogs (and many other species) use UVB to ultimately increase the amount of circulating D3 in their system. They also self regulate exposure to UVB depending on level of D3. In other words - if they have an optimum level of D3 already in their system then adding UVB is not likely going to do any good and will likely cause the frog to avoid the source (i.e., hide). If you are providing D3 from another source you shouldn't need the UVB. 

To make things more difficult - most aquariums we use have glass that filters UVB. There are some types of glass that allow UVB through but it is very expensive and not likely to be found in a typical tank. 

Do you *need* UVB - not really. But the frog does need D3 to be healthy. You choose how the frog gets it.

- Ryan


----------



## Ed

rsain said:


> If you are providing D3 from another source you shouldn't need the UVB.



Sort of... The data that is coming out is that if the frogs (and other taxa) have access to UVB, then they modify thier behavior to reach a higher level of circulating D3 than can be attained through D3 supplied only through the diet. (See for example http://www.academicjournals.org/JPAP/PDF/pdf2011/July/Verschooren et al.pdf). What we are seeing in the broadest terms is that the frogs get by with the D3 supplied through supplementations but if they have the option they increase the D3 in thier bodies. People often forget that D3 is important for many other functions in the body outside of the use of calcium in the bones... 

Your frogs can do fine without any exposure to D3 (and this is documented in many literary sources and by anecdotal practices) but cutting edge is indicating that it benefits them to have some access... 


Ed


----------



## rsain

Ed: I thank you for the clarification!

Sutzor: I think this thread should clear up your question - now you just need to decide what to do.

- ryan


----------



## Shockfrog

Maybe I missed it by accident, but does anyone know where to find research on the commonly used UV-bulbs and their longevity? I've heard that many of them stop emitting UVB after only a couple of months, which would make it a very expensive practice. 

Anyway, I have started an experiment with my E. tricolor 'Echeandia' of which I was told should become alot more yellow when using UVB. They are subadults right now, but I'm wondering what will happen. I also plan to try UVB on young A. silverstonei when they start breeding again. I've seen them being very much attracted to any sunlight that fell through the window into their tanks. This, and the problematic rearing of offspring, made me decide I should definitaly try it.


----------



## Roadrunner

If they can reach higher levels of d3 from uvb exposure, how come they can overdose on oral d3 but don't overdose on uvb producing d3?



Ed said:


> Sort of... The data that is coming out is that if the frogs (and other taxa) have access to UVB, then they modify thier behavior to reach a higher level of circulating D3 than can be attained through D3 supplied only through the diet. (See for example http://www.academicjournals.org/JPAP/PDF/pdf2011/July/Verschooren et al.pdf). What we are seeing in the broadest terms is that the frogs get by with the D3 supplied through supplementations but if they have the option they increase the D3 in thier bodies. People often forget that D3 is important for many other functions in the body outside of the use of calcium in the bones...
> 
> Your frogs can do fine without any exposure to D3 (and this is documented in many literary sources and by anecdotal practices) but cutting edge is indicating that it benefits them to have some access...
> 
> 
> Ed


----------



## Ed

frogfarm said:


> If they can reach higher levels of d3 from uvb exposure, how come they can overdose on oral d3 but don't overdose on uvb producing d3?


Through

1) Feedback inhibition of vitamin D-25 hydroxylase which prevents the conversion of previtamin D3 to D3 in the liver
2) feed back inhibition of the transport of the converted provitamin D3 to the circulation system which results in it converting to supersterols in the skin via continued exposure...,
3) behavioral modification to prevent excess isomerization of provitamin D3 to previtamin D3.... 

Oral ingestion of D3 avoids all of the protection provided by the feedback mechanisms and if excess is ingested resulting in toxicity... which is one of the reasons it was/is used as a rat poison.. 

Ed


----------



## Ed

Shockfrog said:


> Maybe I missed it by accident, but does anyone know where to find research on the commonly used UV-bulbs and their longevity? I've heard that many of them stop emitting UVB after only a couple of months, which would make it a very expensive practice.
> 
> Anyway, I have started an experiment with my E. tricolor 'Echeandia' of which I was told should become alot more yellow when using UVB. They are subadults right now, but I'm wondering what will happen. I also plan to try UVB on young A. silverstonei when they start breeding again. I've seen them being very much attracted to any sunlight that fell through the window into their tanks. This, and the problematic rearing of offspring, made me decide I should definitaly try it.


Typically you won't see a change in yellow pigments using UVB as those are either genetically controlled (pterins) or are taken up from the diet (carotenoids). Typically the carotenoids provided to the frogs consist primarily of beta carotene with lesser amounts of other yellows depending if they are provided in a supplement (very few supply a range of carotenoids) or in some cases potentially through "gut loading" the invertebrates. It is good to keep in mind that carotenoids require a source of lipids in the diet to uptake and absorb carotenoids, and that there is interference between some carotenoids for uptake. This means that if you are using a supplement high in beta carotene it may not matter what carotenoids are in the diet of the invertebrates as the beta carotene ,may prevent the uptake to any significant degree. 

It should be noted that melanin is typically the pigment produced to ward off increased levels of exposure to UVB if required... 

I would suggest trying a variety of carotenoids in the diet of the frogs and the tadpoles as that is more likely to increase pigmentation. 

Ed


----------



## Ed

Shockfrog said:


> Maybe I missed it by accident, but does anyone know where to find research on the commonly used UV-bulbs and their longevity? I've heard that many of them stop emitting UVB after only a couple of months, which would make it a very expensive practice. .


I had forgotten to address this earlier, there are reviews out there that discuss the life span of the bulbs. With most bulbs you should expect to see a decrease in UVB output starting around 6-8 months after starting usage (the differences depend on the type of bulb). I had thought this website UV Lighting for Reptiles: Vivarium Lighting for UVB had the information but it may have been contained in the parts where the website is being updated. Alternatively you can ask Todd (Venustus) as he probably has it saved somewhere. 


Ed


----------



## jacobi

Random thought but I wonder when UV emitting LED's will be used for this purpose (animal husbandry), if they haven't already.

Another slightly less random thought, but according to what I have read, (links are earlier in thread, and a couple others I found) regular glass reduces the quantity but doesn't completely block UV frequencies... Did I read that correctly?


----------



## Ed

jacobi said:


> Random thought but I wonder when UV emitting LED's will be used for this purpose (animal husbandry), if they haven't already.
> 
> Another slightly less random thought, but according to what I have read, (links are earlier in thread, and a couple others I found) regular glass reduces the quantity but doesn't completely block UV frequencies... Did I read that correctly?


It depends on the forumulation of the glass but if I remember correctly, most window and aquarium glass does not allow passage of light below 400 nm. The wavelengths that are required for formation of D3 are below 300 nm.. so regular glass prevents all of the important UV wavelengths. Pure silica dioxide (no soda, no iron) does not block UV light and low iron glass allows for better passage than normal glass. 

If I remember correctly, the LEDs aren't really producing the wavelengths we want (that is a very small niche market) but I could be wrong about that... 

Ed


----------



## skanderson

i have looked far and wide over the internet for uvb producing leds. the only uv leds i found were all in the uva range. i could not locate any in the uvb range.


----------



## Ed

skanderson said:


> i have looked far and wide over the internet for uvb producing leds. the only uv leds i found were all in the uva range. i could not locate any in the uvb range.


I'm waiting for them as well... 

Ed


----------



## stu&shaz

Julio said:


> i am gonna start experimenting with this in some of my frogs, can you guys recomend a good fixture and bulb?


Hi julio,Arcadia also make a T5 which might be of use as an alternative to Grahams cool design. We use this over the top of the viv. Note that we use the euroviv design,and only the back piece of glass is optiwhite(ie lets uvb through),so the frogs have to search out the uv light,ie behaviourally modify thanks Ed. We also have these lights on for only some of the day.I might be wrong but i'm pretty sure the uvb on these bulbs does not deteriorate for a yr.Todd,venutus will be able to confirm or otherwise this for you as he now has these lights,available for you guys stateside.
regards
Stu


----------



## jacobi

Ed said:


> It depends on the forumulation of the glass but if I remember correctly, most window and aquarium glass does not allow passage of light below 400 nm. The wavelengths that are required for formation of D3 are below 300 nm.. so regular glass prevents all of the important UV wavelengths. Pure silica dioxide (no soda, no iron) does not block UV light and low iron glass allows for better passage than normal glass.
> 
> 
> Ed


I misread the graphs on http://www.guardian.com/stellentdev/groups/climaguard/documents/native/gi_004941.pdf and the tables above them don't show the wavelengths, but they do show the percentages of uvb and uva. I guess those are towards 320nm...


----------



## Roadrunner

So if your dartfrog has optimal levels of d3 thru uvb exposure and is eating crickets dusted w/ calcium w/ d3, is there a chance of overdosing on d3 since there is more going in to their system than needed thru feeding?



Ed said:


> Through
> 
> 1) Feedback inhibition of vitamin D-25 hydroxylase which prevents the conversion of previtamin D3 to D3 in the liver
> 2) feed back inhibition of the transport of the converted provitamin D3 to the circulation system which results in it converting to supersterols in the skin via continued exposure...,
> 3) behavioral modification to prevent excess isomerization of provitamin D3 to previtamin D3....
> 
> Oral ingestion of D3 avoids all of the protection provided by the feedback mechanisms and if excess is ingested resulting in toxicity... which is one of the reasons it was/is used as a rat poison..
> 
> Ed


----------



## Ed

frogfarm said:


> So if your dartfrog has optimal levels of d3 thru uvb exposure and is eating crickets dusted w/ calcium w/ d3, is there a chance of overdosing on d3 since there is more going in to their system than needed thru feeding?


No.. The feedback mechanisms and/or behavioral mechanisms kick in and reduce or prevent the conversion of pro-vitamin D3 to D3 (depending on metabolic needs) via UVB exposure so the frog doesn't produce D3 in excess of it's needs. This is why you can overdose on it via oral routes but not through the UV conversion. 

Ed


----------



## bobrez

Sorry cant find a answer, How much uvb will an exo sreen top covered in saran wrap stop. Im thinking most will get thru. Thanks


----------



## Ed

bobrez said:


> Sorry cant find a answer, How much uvb will an exo sreen top covered in saran wrap stop. Im thinking most will get thru. Thanks


Screens block a surprising amount of UVB light. If you can get a copy of this article Evaluation of UVB reduction by materials commonly used in reptile husbandry - Michael Burger - 2007 - Zoo Biology - Wiley Online Library it breaks down the loss through screens. 

Ed


----------



## jacobi

Ed take a look at the graph showing low iron glass uvb transmission. Am I reading that correctly? It seems to show that low iron glass allows less than 10% of uvb and then only above 315nm. Is that comparable to starfire glass?

http://www.guardian.com/stellentdev/groups/climaguard/documents/native/gi_004941.pdf page 38


----------



## Ed

jacobi said:


> Ed take a look at the graph showing low iron glass uvb transmission. Am I reading that correctly? It seems to show that low iron glass allows less than 10% of uvb and then only above 315nm. Is that comparable to starfire glass?
> 
> http://www.guardian.com/stellentdev/groups/climaguard/documents/native/gi_004941.pdf page 38


Starphire is a low iron glass and I don't have the specs on hand to compare it to the charts in that article. You can compare it here http://www.pgo.com/pdf/ppg_starphire.pdf 

Ed


----------



## jacobi

Interesting.

"Transmission: (@5.66 mm thick)
@330nm < 5%"

I wonder why Starfire is said to transmit of UVB... I've heard it multiple times on several forums. I hadnt needed the information before so I hadnt looked into it.


----------



## Ed

jacobi said:


> Interesting.
> 
> "Transmission: (@5.66 mm thick)
> @330nm < 5%"
> 
> I wonder why Starfire is said to transmit of UVB... I've heard it multiple times on several forums. I hadnt needed the information before so I hadnt looked into it.


Because less than 5% could still be above 0... Isn't marketing wonderful. If there are variations in the batches of the iron content, some batches could transmit more of the UVB and others less so that could be an average. 

There is some research that indicates that a higher wavelength could help with D3 formation but you would still need the lower wavelengths to start the process.. In short the converstion to tachsterol can be reconverted to Previtamin D3 by exposure to wavelengths between 315 nm and 340 nm (see Spectral Character of Sunlight Modulates Previtamin D3 )

Ed 

Ed


----------



## ckays

This has been a great read. 

Brings me back to my initial research on Uromastyx. There are extensive discussions and plenty of hard data on any UVB/A Bulb that is out there on those forums, though Ed and others have provided more than enough here i would think. 

I was under the impression it was a wasted effort with dart frogs.
I'll be working on a UVB source for my viv. given this information. 

As a side note, during all that research I did, testing of almost any bulb showed a notable decreases in UVB production after 6 months and many dropped out well before that. However, these are on 8-12 hours a day for those reptiles so I would expect the 8 month range in this hobby if using the bulbs moderately. It is also a matter of perspective at what production level the bulb is rendered ineffective.

I replace my bulb quarterly to ensure steady output. 

Cheers,


----------



## motydesign

well i guess i should stop bugging Ed with the PMs and bring it on here.

ive looked at the lamps that have been suggested and see that they are rated at 61uw/cm2 and have a life of about 1 year. the lamp is suggested to be at 12" from the reptile (amphibian in our case  . this would require the lamps to sit almost on the uv transparent glass. which would introduce a large heat load on the viv.

Azurel introduced me to a LED manufacturer who creates narrow banded UVB diodes. selecting the 295nm led (Ed provided data above that states this is the most efficient nm for transformation of 7-dehydrocholesterol to preD3)
the led has a perfect spectrum









the output is 5- 9 times higher as its at 300 to 500uw/cm2.

ive contacted the manufacturer to find out what the diode has for life span as well as where the drop off in time the out put lies, as well as if the diode output can be lowered with a potentiometer. 

the idea is a .326 hole is cut into a standard viv what ever the height and style. the graph for output followed that they provide for 61uw/cm2 to insure plants are not harmed, and then program a timer for output duration. 










the LED has a 120 degree view angle 

now i just need the manufacturer to answer.... the sad part of this is EACH led is $140.


----------



## Pumilo

motydesign said:


> well i guess i should stop bugging Ed with the PMs and bring it on here.
> 
> ive looked at the lamps that have been suggested and see that they are rated at 61uw/cm2 and have a life of about 1 year. the lamp is suggested to be at 12" from the reptile (amphibian in our case  . this would require the lamps to sit almost on the uv transparent glass. which would introduce a large heat load on the viv.
> 
> Azurel introduced me to a LED manufacturer who creates narrow banded UVB diodes. selecting the 295nm led (Ed provided data above that states this is the most efficient nm for transformation of 7-dehydrocholesterol to preD3)
> the led has a perfect spectrum
> 
> 
> 
> 
> 
> 
> 
> 
> 
> the output is 5- 9 times higher as its at 300 to 500uw/cm2.
> 
> ive contacted the manufacturer to find out what the diode has for life span as well as where the drop off in time the out put lies, as well as if the diode output can be lowered with a potentiometer.
> 
> the idea is a .326 hole is cut into a standard viv what ever the height and style. the graph for output followed that they provide for 61uw/cm2 to insure plants are not harmed, and then program a timer for output duration.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> the LED has a 120 degree view angle
> 
> now i just need the manufacturer to answer.... the sad part of this is EACH led is $140.


Could it be made as a "mobile" unit, and would it's output be sufficient to do the once a week or once every other week, for an hour or two, method? If so, that $140 would still be cheaper to put one unit together that you could move viv to viv, than it would be to try to buy UV systems for every viv or even the cost of modifying a few vivs with special, UV friendly glass or acrylic.


----------



## Azurel

Quick work Brian......Keep us informed on what you find out....


----------



## motydesign

Pumilo said:


> Could it be made as a "mobile" unit, and would it's output be sufficient to do the once a week or once every other week, for an hour or two, method? If so, that $140 would still be cheaper to put one unit together that you could move viv to viv, than it would be to try to buy UV systems for every viv or even the cost of modifying a few vivs with special, UV friendly glass or acrylic.


i dont see why not? my only question is required exposure time something ed may need to answer


----------



## Ed

motydesign said:


> i dont see why not? my only question is required exposure time something ed may need to answer


 
If we are discussing behavioral control of exposure to let the animal get to the range of ideal D3 and bone calcification, then you don't want prevent the ability to access it on a daily basis. If you are attempting to provide some exposure then we can see other studies (like the one I posted to start this thread) where a time limited exposure access can be used. 

Ed


----------



## motydesign

Then that answers our question on dosing a viv like visiting a tanning salon.


----------



## motydesign

motydesign said:


> Then that answers our question on dosing a viv like visiting a tanning salon.


I just realized I need to shut my mouth until I read the other pages of info. I now understand the hardware and a tiny bit of the chemistry. I need to understand the biology before I make a silly comment like "sure why not" hopefully tomorrow I can be alittle more informed on this after reading the provided info.


----------



## Ed

motydesign said:


> I just realized I need to shut my mouth until I read the other pages of info. I now understand the hardware and a tiny bit of the chemistry. I need to understand the biology before I make a silly comment like "sure why not" hopefully tomorrow I can be alittle more informed on this after reading the provided info.


Now you've confused me..... 

Ed


----------



## motydesign

sorry Ed, i caught my self making conclusions and assuming things. then i realized i needed to understand a bit more about exposure limits before jumping to generalized statements. sorry for the confusion, ill have some intelligent questions here in a bit though! not to mention now i see grabbed my quote instead of yours.... yeah that whole post just went array.


----------



## Pumilo

motydesign said:


> sorry Ed, i caught my self making conclusions and assuming things. then i realized i needed to understand a bit more about exposure limits before jumping to generalized statements. sorry for the confusion, ill have some intelligent questions here in a bit though! not to mention now i see grabbed my quote instead of yours.... yeah that whole post just went array.


Moty's been hanging out under the lights too long. Just a little case of LEDstroke!


----------



## motydesign

hahah thank you doug. but really its been from reading all these papers!!! i think i had a mind cramp.

anyway BACK ON SUBJECT!

so reading the papers i find it very interesting that the pumilio seems to choose and call in micro habitats with very low exposures .12uw/cm2! natural habitat has 5-15uw/cm2.

if we agree that the frogs self regulate exposure to UVB then this suggests the pumilio (and i believe auratus if i read right) are likely to be efficient at biosynthesis. 

this being said, most lights are capable of simulating natural habitat at 16uw/cm2 and much higher. 

this in my mind suggest the best application for a hobbiest would be to do one or two things. 
1. have a consistent low exposure with a timed high exposure
2. have a timed high exposure and allow the frog to choose its basking

is there error in thought for my options?


----------



## Ed

motydesign said:


> hahah thank you doug. but really its been from reading all these papers!!! i think i had a mind cramp.
> 
> anyway BACK ON SUBJECT!
> 
> so reading the papers i find it very interesting that the pumilio seems to choose and call in micro habitats with very low exposures .12uw/cm2! natural habitat has 5-15uw/cm2.
> 
> if we agree that the frogs self regulate exposure to UVB then this suggests the pumilio (and i believe auratus if i read right) are likely to be efficient at biosynthesis.
> 
> this being said, most lights are capable of simulating natural habitat at 16uw/cm2 and much higher.
> 
> this in my mind suggest the best application for a hobbiest would be to do one or two things.
> 1. have a consistent low exposure with a timed high exposure
> 2. have a timed high exposure and allow the frog to choose its basking
> 
> is there error in thought for my options?


That pretty much sums up my thoughts on it.. The main point is that you have to be able to provide enough areas that are shielded to allow the frogs to be visible otherwise they may hide all day.... 


Ed


----------



## motydesign

darn this means only one thing.... spend LOTS of money one way or another. 

i called the manufacturer of the LEDs today, waiting on a call back.


----------



## Reef_Haven

what are early symptoms of D3 overdosing? I know seizures and heart failure, but are there some indications you are over supplementing, before they become this drastic?

Also, I noticed a couple people mentioned their frogs seem attracted to a shaft of sunlight, but isn't it likely that shaft does not contain UVB; since it most likely is coming through a glass window?


----------



## Ed

Reef_Haven said:


> what are early symptoms of D3 overdosing? I know seizures and heart failure, but are there some indications you are over supplementing, before they become this drastic?
> 
> Also, I noticed a couple people mentioned their frogs seem attracted to a shaft of sunlight, but isn't it likely that shaft does not contain UVB; since it most likely is coming through a glass window?


You cannot over dose on D3 produced by UVB exposure. You cannot overdose on D3 even if you combine an oral source of D3 with UVB exposure unless you have already overdosed on D3 orally. 

There is nothing to suggest that the frogs are not programmed to bask to modify body temperatures to higher levels than found in the enclosure. Often the temperatures considered ideal by the hobby are less than the frogs may experience in the wild... 

Oral overdoses of D3 result in anorexia, depression, polyuria/po;lydipsia, weight loss, calcification of soft tissues, 

Ed


----------



## rsain

motydesign said:


> snip
> 1. have a consistent low exposure with a timed high exposure
> 2. have a timed high exposure and allow the frog to choose its basking
> 
> is there error in thought for my options?


Maybe I'm off here - but I foresee a problem with number 2 based on the post and article by ed:



Ed said:


> snip
> 
> Using O. pumilio as a model there isn't any indication that the frogs can actually see UVB (or UVA) light see http://core.ecu.edu/biol/summersk/s...ion in spectral reflectance in D. pumilio.pdf as they lack the structures in thier eyes to see into that frequency (specifically see





> There is little or no evidence that D. pumilio does have UV sensitive cones (E. Loew, pers comm.) which would allow these frogs to percieve reflectance in that region of the electromagnetic spectrum. Morever our measurements suggest that all the different morphs of D. pumilio have very little reflectance in the UV, implying that UV colours may not be important for social interactions in this species





Ed said:


> We also know that the frogs avoid excess exposure to UVB see http://people.oregonstate.edu/~blaustea/pdfs/HanBiotropica2007.pdf .. which indicates that the frogs can detect UV exposure, but we aren't sure of the exact method but it is probable that it may at least depend on the circulating levels of vitamin D3...
> 
> Some further comments,
> 
> Ed


If the frog cannot "see" UVB then you are going to have a problem with the frog "knowing" when and where to go bask. Granted - operant conditioning will eventually kick in but it will take a few weeks (guess) for the frog to "figure it out". 

With number 1 the frog will figure out where the UVB exposure spots are quicker (it's going to 'stumble' across them as it wanders through the viv) - and will wait in that spot until the d3 feedback loops kick in. 

- ryan


----------



## motydesign

ryan i think that you forget that the methods of providing UVB will actually dose the complete viv. lets say the 120 view angle led in a 40 Breeder vert (gives you a 2' from frog to LED) in this situation the 120 view angle 2' above the frog is providing a 7' diameter circle. clearly larger than the floor of a 18X16 40 breeder floor. 


the other is a T5HO bulb with a UV transparent top evenly dosing the entire viv at 16uW/cm2 at the top with a decay of power by the time it reaces the floor. 

so #2 still works. the frogs are out the LED is on, UVB is being administered at this point the frog will go to cover if it no longer needs the UVB. also consider this is a long term application with daily exposure.


----------



## Ed

rsain said:


> If the frog cannot "see" UVB then you are going to have a problem with the frog "knowing" when and where to go bask. Granted - operant conditioning will eventually kick in but it will take a few weeks (guess) for the frog to "figure it out".


This ignores the possibility of other methods of signaling such as the pineal organ... 

Ed


----------



## motydesign

Ed said:


> Oral overdoses of D3 result in anorexia, *depression*, polyuria/po;lydipsia, weight loss, calcification of soft tissues,
> 
> Ed


does depression indicate intelligence? or should we assimilate depression (lack of activity) with stress?


----------



## Reef_Haven

Ed said:


> There is nothing to suggest that the frogs are not programmed to bask to modify body temperatures to higher levels than found in the enclosure. Often the temperatures considered ideal by the hobby are less than the frogs may experience in the wild...
> 
> Ed


Yes,
That was the point I was trying to make, people shouldn't assume the frogs are basking in sunlight in an attempt to gain UVB. If there is no UVB in the sunlight coming thru the window, they are merely trying to adjust their body temp or maybe it just feels nice, but they aren't actually trying to obtain UVB.


----------



## rsain

motydesign said:


> ryan i think that you forget that the methods of providing UVB will actually dose the complete viv.
> snip


Ahh yes - this is exactly what I was missing. LOL. Totally forgot about the 120deg. I'm sitting here thinking about a small spot where UVB would be available. 

Based on that you wouldn't need to worry about my worry. 

- ryan


----------



## motydesign

Reef_Haven said:


> Yes,
> That was the point I was trying to make, people shouldn't assume the frogs are basking in sunlight in an attempt to gain UVB. If there is no UVB in the sunlight coming thru the window, they are merely trying to adjust their body temp or maybe it just feels nice, but they aren't actually trying to obtain UVB.


this doesnt take into consideration the COMPLETE light spectrum including UVA but minus UVB


----------



## rsain

motydesign said:


> does depression indicate intelligence? or do we assimilate depression with stress?


_getting a bit off topic but I'll bite_

Now were sneaking up a little closer on my field. 

That's a heavily loaded question (in many many ways). First, if you apply a natural scientific (read - not soft psychology stuff) argument then depression is nothing more than a label for a class (i.e., list) of behaviors. As a result we cannot say that a frog "has" depression. It can act in a depressed fashion (list behaviors here) - that is all. But the label does not explain the behavior (this would be reification and is a no no scientifically). 

Second - intelligence - by what standard? WISC? WAIS? etc, etc. The evidence posted earlier indicates at least operant level of learning. That's pretty smart in my book. Of course, operant conditioning is very widespread. 



[/hijack]

- ryan


----------



## motydesign

rsain said:


> _getting a bit off topic but I'll bite_
> 
> Now were sneaking up a little closer on my field.
> 
> That's a heavily loaded question (in many many ways). First, if you apply a natural scientific (read - not soft psychology stuff) argument then depression is nothing more than a label for a class (i.e., list) of behaviors. As a result we cannot say that a frog "has" depression. It can act in a depressed fashion (list behaviors here) - that is all. But the label does not explain the behavior (this would be reification and is a no no scientifically).
> 
> Second - intelligence - by what standard? WISC? WAIS? etc, etc. The evidence posted earlier indicates at least operant level of learning. That's pretty smart in my book. Of course, operant conditioning is very widespread.
> 
> 
> 
> [/hijack]
> 
> - ryan


thats why i asked for clarification. was wondering what Ed implied with the word he used.


----------



## Ed

rsain said:


> _getting a bit off topic but I'll bite_
> 
> Now were sneaking up a little closer on my field.
> 
> That's a heavily loaded question (in many many ways). First, if you apply a natural scientific (read - not soft psychology stuff) argument then depression is nothing more than a label for a class (i.e., list) of behaviors. As a result we cannot say that a frog "has" depression. It can act in a depressed fashion (list behaviors here) - that is all. But the label does not explain the behavior (this would be reification and is a no no scientifically).
> 
> Second - intelligence - by what standard? WISC? WAIS? etc, etc. The evidence posted earlier indicates at least operant level of learning. That's pretty smart in my book. Of course, operant conditioning is very widespread.
> 
> 
> 
> [/hijack]
> 
> - ryan


You guys are reading too much into it... the context here is that the animal is showing less activity, alertness, is just off from normal behaviors or in non-medical parlance "ain't doing right"... 


Ed


----------



## Reef_Haven

motydesign said:


> this doesnt take into consideration the COMPLETE light spectrum including UVA but minus UVB


Care to expound on this?
I understand they are getting the rest of the light spectrum, but don't see why one would think they are basking in an attempt to absorb more UVB if it is not present.


----------



## Ed

Reef_Haven said:


> Care to expound on this?
> I understand they are getting the rest of the light spectrum, but don't see why one would think they are basking in an attempt to absorb more UVB if it is not present.


Hypothetically, if the amount of basking is in part determined by circulating levels of D3 metabolites instead of amount of exposure (since other animals differentially bask depending to modify levels of circulating metabolites), then the frog could easily spend more time basking than it would otherwise to modify body temperature since it wasn't reaching ideal levels of metabolites in the circulating blood volume. 
There is at least one good study on chameleons that demonstrated this to occur. 

Ed


----------



## motydesign

/\ what he said


----------



## rsain

Ed said:


> You guys are reading too much into it... the context here is that the animal is showing less activity, alertness, is just off from normal behaviors or in non-medical parlance "ain't doing right"...
> Ed


Agreed wholeheartedly. 

I wish my field understood this basic point about what depression is.  

- ryan


----------



## Judy S

I hate it when I have to admit to resorting to the dictionary: polyuria/po;lydipsia,---it just reinforces how little one knows...you guys are so intimidating...props to all for discussing the science and not personal things as are posted too often...


----------



## frogfreak

Ed said:


> "ain't doing right"...
> 
> 
> Ed


Why didn't you say that in the first place? Now I get it!


----------



## motydesign

i received a call at butt crack of dawn and found out the LEDs are good for 5000-7000hrs, that the out put is lineal with use of their power supply and that there is a decay of output. Waiting on graphs of the lineal output to V input, as well as the decay. this would most likely require a meter and monthly monitoring to insure the unit is putting out the UVB at set levels.


----------



## EvilLost

Perhaps somewhat offtopic but I was under the impression that UV does not pass through glass....can someone clarify on this?


I'm (blindly) guessing that it has to do with the wavelengths of the UV and the spacing of the crystallization of the glass?


----------



## motydesign

no it doesnt, there are a few articles you need to read in this thread that will enlighten you.


----------



## EvilLost

yea i've tagged this thread for a thorough reading, its a bit long to grasp it all at once

to the books!


----------



## motydesign

its not the thread, its the articles haaha

i think i want to start a topic like this every week. i am going to need Eds help, but i would love to learn something like this as often as possible. maybe the general theme is understanding whats going on in you viv.
i hate to say it, but i really miss college  all five years of it


----------



## Ed

motydesign said:


> its not the thread, its the articles haaha
> 
> i think i want to start a topic like this every week. i am going to need Eds help, but i would love to learn something like this as often as possible. maybe the general theme is understanding whats going on in you viv.
> i hate to say it, but i really miss college  all five years of it


Understanding what is going on in the tank is the ideal goal. I've spent decades working on it and I'm still learning all the time.... 

Ed


----------



## Noxz

I realized that these animals needed UVB long before I found all the contradictory threads of having a light just for the plants because they are normally on the ground, under the shade, away form light in their natural habitat.
I am currently planning on making a triple vivarium (shared/dividing walls) and was planning on using a 36" ReptiSun for the three, so each would get 12" of light.(ea one is about 10gal, less than 24" tall(18"?)) I was not planning on using a second light just for the plants or for non UVB exposure periods. Possibly a ceramic heat lamp for regulating temperatures at night. I was thinking that the more UVB the better, so I was thinking to go with a 10%... but after reading a bit it seems that I should go lower because of trying to hide from the light, maybe a 5.0 or even down to a 2.0 if it is being used as the only light. The supplier I was planning on getting the light/hood from does not carry 2.0 but they do have 5.0 and 10.0 . Of course I would use a fruitfly proof screen top, or at least screen where the light is so the UVB actually goes through.
What about hanging UVB lights instead of resting them on the vivariums?
What about misting with a screen with the light? how waterproof/shatterproof are reptisuns? 
Just a few thoughts and questions before my tadpoles need their vivarium built.


----------



## Ed

Noxz said:


> I realized that these animals needed UVB long before I found all the contradictory threads of having a light just for the plants because they are normally on the ground, under the shade, away form light in their natural habitat.
> I am currently planning on making a triple vivarium (shared/dividing walls) and was planning on using a 36" ReptiSun for the three, so each would get 12" of light.(ea one is about 10gal, less than 24" tall(18"?)) I was not planning on using a second light just for the plants or for non UVB exposure periods. Possibly a ceramic heat lamp for regulating temperatures at night. I was thinking that the more UVB the better, so I was thinking to go with a 10%... but after reading a bit it seems that I should go lower because of trying to hide from the light, maybe a 5.0 or even down to a 2.0 if it is being used as the only light. The supplier I was planning on getting the light/hood from does not carry 2.0 but they do have 5.0 and 10.0 . Of course I would use a fruitfly proof screen top, or at least screen where the light is so the UVB actually goes through.
> What about hanging UVB lights instead of resting them on the vivariums?
> What about misting with a screen with the light? how waterproof/shatterproof are reptisuns?
> Just a few thoughts and questions before my tadpoles need their vivarium built.


If you use a mesh that is tight enough to prevent any flies from escaping, you will block virtually all of the UVB light. Screens on enclosures are a documented source of decreased UVB penetration into the tank with the smaller the mesh the greater the blockage. 

This was discussed earlier in the thread see http://www.dendroboard.com/forum/sc...68-uvb-exposure-dendrobates-6.html#post682571 

Ed


----------



## bobrez

Ed said:


> If you use a mesh that is tight enough to prevent any flies from escaping, you will block virtually all of the UVB light. Screens on enclosures are a documented source of decreased UVB penetration into the tank with the smaller the mesh the greater the blockage.
> 
> This was discussed earlier in the thread see http://www.dendroboard.com/forum/sc...68-uvb-exposure-dendrobates-6.html#post682571
> 
> Ed


I couldnt access what ed was linking, and not having a meter of my own googled it and found a website and groups who have tested it UV Lighting for Reptiles: Fluorescent Tubes with Mesh and Screen
Showing that a screen only blocks a little and goes on, that plastic and glass blocks virtually all uvb.
So it easies my mind and initial thought that screen can be used effectively for the purpose of uvb exposure.


----------



## Ed

bobrez said:


> I couldnt access what ed was linking, and not having a meter of my own googled it and found a website and groups who have tested it UV Lighting for Reptiles: Fluorescent Tubes with Mesh and Screen
> Showing that a screen only blocks a little and goes on, that plastic and glass blocks virtually all uvb.
> So it easies my mind and initial thought that screen can be used effectively for the purpose of uvb exposure.


That is actually not the article I linked. It is a simplified discussion of the actual article that doesn't examine a lot of the potential materials... Mesh fine enough to stop fruit flies can stop 100% of UVB. 

Ed


----------



## bobrez

Ed said:


> That is actually not the article I linked.


I know said i couldnt access it



Ed said:


> It is a simplified discussion of the actual article that doesn't examine a lot of the potential materials... Mesh fine enough to stop fruit flies can stop 100% of UVB. Ed


And my question was of exo screen top, which i dont think is ff proof.

The full article is bottom this page in pdf Chameleon lighting and my take on it, that the screen will actually act as a sort of rainforest canopy as to reduce uvb but still provide it?
Isnt this just perfect for dart frogs?


----------



## Ed

bobrez said:


> And my question was of exo screen top, which i dont think is ff proof?


Okay how was I to distinguish that you were speaking about exo-terra screen since the only screen discussed before that post was fruit fly proof?? 

I'm not sure that going for a rainforest canopy is the correct model for a number of the species.. for example, a number of species actually can reach thier greatest density in disturbed or secondary growth where there is greater unobstructed light penetration. I think a better option is to use a UV transparent canopy (since tachysterol reverts to provitamin D3 at a higher nm point but still in the spectrum that is often blocked by typical glass but starphire and solacryl both pass it).. and then provide a minimally impacted exposure point (I'm drilling some 1.5 inch holes in the solacryl) with a timed exposure (I'm going to provide the option to regulate between 11 and 2 pm). 

Ed


----------



## Judy S

what will you use to prevent FF escape in those 1.5 holes?? " drilling some 1.5 inch holes in the solacryl"


----------



## Ed

Judy S said:


> what will you use to prevent FF escape in those 1.5 holes?? " drilling some 1.5 inch holes in the solacryl"


 
Well, the tank is 36 inches high... so that will cut it down some as will the addition of bait stations.. I'll still probably have to use a closable water bottle for my beverages while I'm working on the computer... 

Ed


----------



## motydesign

Ed said:


> Well, the tank is 36 inches high... so that will cut it down some as will the addition of bait stations.. I'll still probably have to use a closable water bottle for my beverages while I'm working on the computer...
> 
> Ed


hahah many of drinks have been lost in my home due to this


----------



## Pumilo

Think of it as a "protein drink".


----------



## motydesign

ed, what are you planning on having for exposure range through the tank during your "ON" period? will you be using a radiometer of some sort to measure initial set up and monitor?


----------



## Ed

motydesign said:


> ed, what are you planning on having for exposure range through the tank during your "ON" period? will you be using a radiometer of some sort to measure initial set up and monitor?


No meters yet, budget doesn't allow it..(I blew my discretionary budget on the solacryl). I'm going to have two different UVB producing T5HO bulbs and the bulbs are going to be on timers to come on at different times. The lower UVB production bulb will come on first and shut off last while the higher UVB bulb will come on second and shut off earlier (I'm thinking 10 am and 3 pm for the lower UVB production and 11 and 1 pm for the higher levels) which would mimic some of the documented activity periods (before 10 and after 3 pm). I'll also adjust thier misting cycle with a short 10 second mist in the am around 7 am and a longer 30 second misting around 4 pm (to start out with, if the tank gets too dry, I'll increase it or add a longer cycle after the lights are out to mimic an evening rainstorm). 
This will be further controlled by the holes in the solacryl which will control the spread of the UVB in the tank allowing for both horizontal and verticle intensity gradients so the frogs can behaviorally regulate behaviors as well. At this moment the closest the frogs can get to the lights are about 5 inches. 


Ed


----------



## motydesign

Ed said:


> At this moment the closest the frogs can get to the lights are about 5 inches.
> 
> 
> Ed


ahhh thats kinda what i was looking for! i read up on your solacryl and i am curious why you went with voids? it seems the product does 92% transmittance. so now im curious of your interest in the 8% missed?


----------



## bobrez

I belive thats 92% uva and 0% uvb for solacryl so holes are nessary for any transmitence. IDK but thats what it looks like.


----------



## Ed

motydesign said:


> ahhh thats kinda what i was looking for! i read up on your solacryl and i am curious why you went with voids? it seems the product does 92% transmittance. so now im curious of your interest in the 8% missed?


Because I get 100% transmission with the voids... the UVA is important as well for the reverse reaction where tachysterol is converted back via the exposure to levels between @340=400 nm... The frogs should also be able to see in the near UVA (even if they don't see into the regular UVA). 

Ed


----------



## ckays

I'm looking forward to your findings on this.


----------



## motydesign

Ed can you post me up something on what tachysterol is and does and such? my googling isnt finding me the info im looking for. also maybe a bit more info on the 340-400nm spectra (thats an easy and cheap one to replicate  )


----------



## Ed

motydesign said:


> Ed can you post me up something on what tachysterol is and does and such? my googling isnt finding me the info im looking for. also maybe a bit more info on the 340-400nm spectra (thats an easy and cheap one to replicate  )


It is part of the feed back mechanism that prevents excess D3 from being created via UVB exposure. When previtamin D3 is being created, further exposure converts it to tachysterol and lumisterol which are biologically inert (thus acting as an effective feedback control to prevent overproduction of D3) but can be reconverted back to previtamin D3 through exposure to UVA. Export of previtamin D3 from the skin prevents the further conversion to tachysterol and lumisterol, allowing the animals to adjust exposure and control circulating levels of D3 (and it's metabolites).. 

The process is very highly conserved across taxa and this is the first free access copy that contains a good break down of it is this editorial see http://www.ajcn.org/content/67/6/1108.full.pdf 

Ed


----------



## motydesign

Ed, im finding a little contradiction in this page (which ref. Webb and STAMP TBC) in what spectra is the most effective wavelengths that 7-dehydrocholestoral is absorbed (they are stating 270-290nm)

tachysterol seems to be some what a reserve if you will for PreD3 that easly converted back and forth with UVA and B. I think i understand that once the maximum D3 is produced (15%available) then it will start converting to the tachysterol. this i am now assuming since i havent read anything on it, is the part that tells the frog to start limiting its exposure, through detection in the pineal glad of the tachysterol levels. but what is the point of using UVA to convert the tachysterol back over to preD3? when there should be enough 7-dehydrocholestoral just to continue creating it through the UVB process?

would the levels of tachysterol need to flucuate so that the frog can regulate or is there a way for them to discard the tachysterol if there is no need for the reserve?


----------



## Ed

motydesign said:


> Ed, im finding a little contradiction in this page (which ref. Webb and STAMP TBC) in what spectra is the most effective wavelengths that 7-dehydrocholestoral is absorbed (they are stating 270-290nm)


It's an editorial and while it provides a good explanation it shouldn't be considered authoritative since it really doesn't have to be subject to the scrutiny as a regular research paper.. It was simply the best free sample that broke it down with a diagram...



motydesign said:


> tachysterol seems to be some what a reserve if you will for PreD3 that easly converted back and forth with UVA and B. I think i understand that once the maximum D3 is produced (15%available) then it will start converting to the tachysterol.


Not quite... you will be getting conversion to it (and the other secosterols) during the whole process. The reason it stays at around 15% is more probably due to the rate of export of the pre-D3 for reaction in the liver (and kidneys) combined with the reaction into the alternate secosterols and reversiable conversion back to pre-D3.. The reaction is going to be part of the feedback loop.. so you don't get surplus (of what is really a pre-hormone and not a vitamin) of preD3 which is biologically active, the feed back allows the conversion (and then conversion back) to the alternate non-metabolic active secosterols (like tachysterol). It would be a problem for animals that could be in the sun for a significant period of time, if there was no reversiable conversion of the nonmetabolic secosterols as exposure to sunlight would result in excess unusable molecules cluttering up the cells... which would have to then either export them as waste or degrade them. 



motydesign said:


> this i am now assuming since i havent read anything on it, is the part that tells the frog to start limiting its exposure, through detection in the pineal glad of the tachysterol levels. but what is the point of using UVA to convert the tachysterol back over to preD3? when there should be enough 7-dehydrocholestoral just to continue creating it through the UVB process?


The pineal gland won't detect tachysterol since it isn't exported from the skin cells into the circulating system. Also the pineal eye in frogs contains photoreceptors that potentially can detect UVB/UVA. The circulating levels of D3, pre-D3 and some of the other metabolites (but not tachysterol/lumisterol or other non-active secosterols) can play a part in the feedback mechanisms which can control behavioral basking. 

Ed


----------



## Judy S

back to the world of us-who-do-not-have-the-science background: I have seen the use of a Saran wrap material used to control humidity...with suspended lights...does this material allow more of the "good" light spectrum to enter the viv???


----------



## Ed

Judy S said:


> back to the world of us-who-do-not-have-the-science background: I have seen the use of a Saran wrap material used to control humidity...with suspended lights...does this material allow more of the "good" light spectrum to enter the viv???


Yes, but it doesn't help with the security of the enclosure... 

Ed


----------



## motydesign

Judy S said:


> back to the world of us-who-do-not-have-the-science background: I have seen the use of a Saran wrap material used to control humidity...with suspended lights...does this material allow more of the "good" light spectrum to enter the viv???


 yes some can

Judy, im in NO way am i science related (im an engineer... mathematics) i am just trying to use logical thinking to understand the chemistry and biology. 


Saran wrap 
http://www.dendroboard.com/forum/parts-construction/26516-uv-transmittance-plastic-wrap.html


Ed wow, i completely missed the boat on this one.



Ed said:


> Not quite... you will be getting conversion to it (and the other secosterols) during the whole process. The reason it stays at around 15% is more probably due to the rate of export of the pre-D3 for reaction in the liver (and kidneys) combined with the reaction into the alternate secosterols and reversiable conversion back to pre-D3.. The reaction is going to be part of the feedback loop.. so you don't get surplus (of what is really a pre-hormone and not a vitamin) of preD3 which is biologically active, the feed back allows the conversion (and then conversion back) to the alternate non-metabolic active secosterols (like tachysterol). It would be a problem for animals that could be in the sun for a significant period of time, if there was no reversiable conversion of the nonmetabolic secosterols as exposure to sunlight would result in excess unusable molecules cluttering up the cells... which would have to then either export them as waste or degrade them.


so this is pushing the idea that the full spectrum is needed not just the 295nm length. 



Ed said:


> The pineal gland won't detect tachysterol since it isn't exported from the skin cells into the circulating system. Also the pineal eye in frogs contains photoreceptors that potentially can detect UVB/UVA. The circulating levels of D3, pre-D3 and some of the other metabolites (but not tachysterol/lumisterol or other non-active secosterols) can play a part in the feedback mechanisms which can control behavioral basking.
> 
> Ed


so do we know how they receive the feedback mechanism? im confused what tells them enough is enough?



Ed said:


> Yes, but it doesn't help with the security of the enclosure...
> 
> Ed


says the man with open HOLES in the top his vivs


----------



## Ed

motydesign said:


> so this is pushing the idea that the full spectrum is needed not just the 295nm length.


It is pushing that the spectra from at least 295 through 400 needs to be there. 



motydesign said:


> so do we know how they receive the feedback mechanism? im confused what tells them enough is enough?


There are a number of potential points where feedback inhibition kicks into gear to prevent excess D3 from being formed but the area where I would look for the behavioral controls would be in the brain, and I would start in the hypothalamus. (we know that the kidney helps control levels of the 1,25-dihydroxyvitamin D3 through synthesis and degredation). It is known that there are receptors for vitamin D3 (which we also know is really a hormone and not a vitamin) in both the brain and the hypothalamus... Since the behavioral regulation would be to sustain an optimal level of D3 and it's metabolites circulating in the blood volume where they would be available for demand, the hypothalamus is the logical place to look since that is where the endocrine system meets the autonomic nervous system.... 
(See for example http://www.direct-ms.org/pdf/VitDGenScience/D recptor brain.pdf )




motydesign said:


> says the man with open HOLES in the top his vivs


What can I say? 

Ed


----------



## motydesign

thank you Ed, this is a great help. im at the point where i realize the implementation of UV.this is going to be difficult, but the most important aspect is knowing what we are producing and what levels we are exposing the tank to. frequent measuring will be required since we will not be able to see most of the light (the 390nm will start being visible a slight purple )

well i guess its time to stop talking and start doing.


----------



## motydesign

re read the article since i missed the idea the first time, so now i have more questions. i orginally thought that the creation of tachysterol and lumisterol we forms of reserve, Ed directed they were not. now im curious what they are used for? Ed can you inform me? or let me know what they have found here?
The []overirradiation products[] of previtamin D and tachysterol: Toxisterols - Boomsma - 2010 - Recueil des Travaux Chimiques des Pays-Bas - Wiley Online Library


then what is happening with the pyrocalciferol and isopyrocalciferol? these also are secosteriods since they do not have broken 9/10 carbon bonds, which i assume unlike the inert compounds above have a direct influence on the host. can you elaborate a bit on this as well?


thanks for your help Ed!


----------



## Ed

motydesign said:


> re read the article since i missed the idea the first time, so now i have more questions. i orginally thought that the creation of tachysterol and lumisterol we forms of reserve, Ed directed they were not. now im curious what they are used for? Ed can you inform me? or let me know what they have found here?
> The []overirradiation products[] of previtamin D and tachysterol: Toxisterols - Boomsma - 2010 - Recueil des Travaux Chimiques des Pays-Bas - Wiley Online Library
> then what is happening with the pyrocalciferol and isopyrocalciferol? these also are secosteriods since they do not have broken 9/10 carbon bonds, which i assume unlike the inert compounds above have a direct influence on the host. can you elaborate a bit on this as well?


In the link you provided, above, those alternate forms were the result on conditions unlikely to be seen inside of a cell (or body).. specifically the conditions that prevent the isomerization to the active forms... 

With respect to the tachysterol and lumisterol (and the other secosterols formed with lumisterol), if you look at that editorial you'll notice that the reaction arrow goes both way indicating a reversiable reaction. This is why it is part of the feed back controls (if you want the math, I'm sure you can find a kinematics rate equation in the literature.. ) and helps to prevent the over-conversion to the metabolically active form. Tachysterol and lumnisterol are considered to be biologically inert except for the reversiable reaction to pre-D3. The cell doesn't store them or maintain them except as part of the reversiable reaction (which is why it isn't considered a reserve).,,, 

Does that help? It really is logical... 

Ed


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## motydesign

good to know all i got from the abstract was they exposed to prolong periods of UV i was hoping it said what these described compounds ended up doing.

yeah it does make sense i guess. but why is it producing secosteriods just to turn around and reverse the process? ive learned nature doesnt waste energy on purpose hahaah


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## Ed

motydesign said:


> yeah it does make sense i guess. but why is it producing secosteriods just to turn around and reverse the process? ive learned nature doesnt waste energy on purpose hahaah


It isn't wasting energy.. the energetic cost is being supplied by the UV light.. if you think about it, it is not only absorbing the energy to convert to metabolically active products but the second reaction is also absorbing energy with both protecting the cell from UV damage.... when considering these things you have to look at the larger picture as well as the smaller...


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## Ed

I should also add, that is why it functions are part of the feedback process. It prevents excess formation of D3 products which would cause damage to the animal via calcification of soft tissues (like the kidneys). The conversion to the other secosterols prevents excess from building up in the skin cells (since the materials inside the cell are not part of the behavioral signaling mechanism). It isn't wasted energy..


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## motydesign

AHHHH NOW that makes sense!
so now the dietary supplementing will insure there is enough dehydrocolesterol available for conversion to preD3 correct? 


once again thank you for your help in making this understandable!


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## Ed

motydesign said:


> AHHHH NOW that makes sense!
> so now the dietary supplementing will insure there is enough dehydrocolesterol available for conversion to preD3 correct?
> 
> 
> once again thank you for your help in making this understandable!


Dietary supplementation isn't with a product that converts to preD3 or even proD3. The supplements contain the actual D3 hormone (1,25-dihydroxycholecalciferol)...so they bypass the majority of the feedback protections and can result in overdosing which results in issues like liver damage, calcification of soft tissues and the kidneys. However the D3 in the blood can result in no or less conversion in the cells. 

Ed


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## motydesign

Ed said:


> Dietary supplementation isn't with a product that converts to preD3 or even proD3. The supplements contain the actual D3 hormone (1,25-dihydroxycholecalciferol)...so they bypass the majority of the feedback protections and can result in overdosing which results in issues like liver damage, calcification of soft tissues and the kidneys. However the D3 in the blood can result in no or less conversion in the cells.
> 
> Ed


damn it Ed now were does the reserve od 7-dehydro come from, im starting to become lost now


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## Ed

motydesign said:


> damn it Ed now were does the reserve od 7-dehydro come from, im starting to become lost now


 
Laughs.. your making it too complicated it is a basic flow chart with some circles in it.. the original materials are the result of sterol synthesis.. using an appropriate start, I'm tired but I would guess that cholesterol is the place it would start.. the cells convert it via various enzymes into the proD3 molecules.


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## mcaiger53

Great thread. 
Ed, could you point me in the direction of the uvb t5ho's you are using? I have only been able to find t8's. Do they supply the uva 340-400nm you have mentioned or are you using something else for that? I have seen a lot of reasonably priced uv led's in that range. 
Thanks, mike.


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## motydesign

Alright I'm letting it be then cause I'm over thinking it like you said. First thought that I had was our suplemintation with magnisum and phosporus was part of calcification of kidneys ... Should of stayed with that though after I read about the study on guine pigs and their diets related to that.


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## Ed

mcaiger53 said:


> Great thread.
> Ed, could you point me in the direction of the uvb t5ho's you are using? I have only been able to find t8's. Do they supply the uva 340-400nm you have mentioned or are you using something else for that? I have seen a lot of reasonably priced uv led's in that range.
> Thanks, mike.


The bulbs I'm adding to the top have the spectra that runs the UVB peak (290-300 nm) as well as the UVA spectrum. I'm sending you a pm so I don't provide feedback. 

Ed


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## Ed

motydesign said:


> Alright I'm letting it be then cause I'm over thinking it like you said. First thought that I had was our suplemintation with magnisum and phosporus was part of calcification of kidneys ... Should of stayed with that though after I read about the study on guine pigs and their diets related to that.


It would be part of the issue if there was an oversupplementation of D3... 

Ed


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## Judy S

Ed said:


> That is actually not the article I linked. It is a simplified discussion of the actual article that doesn't examine a lot of the potential materials... Mesh fine enough to stop fruit flies can stop 100% of UVB.
> 
> Ed


so if most of us use glass for at least part of the tops of the vivs and the UVA and some UVB wavelengths are blocked by ordinary glass...and mesh with holes small enough to eliminate FF escape, what is the best way for most of us to do the very best for our vivariums???


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## Ed

Judy S said:


> so if most of us use glass for at least part of the tops of the vivs and the UVA and some UVB wavelengths are blocked by ordinary glass...and mesh with holes small enough to eliminate FF escape, what is the best way for most of us to do the very best for our vivariums???


Judy,
I'm not suggesting that everyone should switch over to UVB exposure or retrofit thier enclosures since we know that the frogs do okay on just the supplementation. 
I'm adding it on a going forward basis since there are some issues that I think this may help resolve. I'm really waiting for decent LED's that have the correct activity spectrum to come down in price as that will be easy to add to the enclosures on a going forward basis. 

Ed


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## Judy S

When that point in time comes, and it will...I know that you and LightMyReptiles will be right on it. Thanks for the reassurance that supplements are forestalling certain subtle issues of frog husbandry.


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## parkanz2

Ed said:


> Judy,
> I'm not suggesting that everyone should switch over to UVB exposure or retrofit thier enclosures since we know that the frogs do okay on just the supplementation.
> I'm adding it on a going forward basis since there are some issues that I think this may help resolve. I'm really waiting for decent LED's that have the correct activity spectrum to come down in price as that will be easy to add to the enclosures on a going forward basis.
> 
> Ed


Have you thought much about mounting techniques for UVB LEDs when we finally get them? If you can get lenses for them (assuming the lenses don't filter out a significant amount of the desired wavelengths,) and they don't run too hot, I'd wonder if you could actually mount the LED so it protrudes through the canopy material which would eliminate filtering of UVB by various materials and the need for gaps/holes allowing fruit fly escapes.

Getting a bit ahead of things since we don't actually have access to any UVB producing LEDs but one can dream.


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## Pumilo

parkanz2 said:


> Have you thought much about mounting techniques for UVB LEDs when we finally get them? If you can get lenses for them (assuming the lenses don't filter out a significant amount of the desired wavelengths,) and they don't run too hot, I'd wonder if you could actually mount the LED so it protrudes through the canopy material which would eliminate filtering of UVB by various materials and the need for gaps/holes allowing fruit fly escapes.
> Getting a bit ahead of things since we don't actually have access to any UVB producing LEDs but one can dream.


This is the method that Motydesign is working on as detailed in the following quotes. Hopefully, his research will lead to a portable system that can be simply moved from viv to viv with the only modification to each viv being a simple hole drilled in it. Then when you move it, the hole could be simply plugged with a cork or whatever. The initial expense may be rather high but not if you consider that the same system could service multiple vivs.



Pumilo said:


> That would be pretty sweet. How about a single UVB emitting LED that could be simply placed into the same 5/8" size hole that we drill for our misters? That could eliminate the problems associated with getting the proper glass or plexi required for UVB penetration. It could be simply added in regardless of any existing lighting system.






motydesign said:


> well i guess i should stop bugging Ed with the PMs and bring it on here.
> 
> ive looked at the lamps that have been suggested and see that they are rated at 61uw/cm2 and have a life of about 1 year. the lamp is suggested to be at 12" from the reptile (amphibian in our case  . this would require the lamps to sit almost on the uv transparent glass. which would introduce a large heat load on the viv.
> 
> Azurel introduced me to a LED manufacturer who creates narrow banded UVB diodes. selecting the 295nm led (Ed provided data above that states this is the most efficient nm for transformation of 7-dehydrocholesterol to preD3)
> the led has a perfect spectrum
> 
> 
> 
> 
> 
> 
> 
> 
> 
> the output is 5- 9 times higher as its at 300 to 500uw/cm2.
> 
> ive contacted the manufacturer to find out what the diode has for life span as well as where the drop off in time the out put lies, as well as if the diode output can be lowered with a potentiometer.
> 
> the idea is a .326 hole is cut into a standard viv what ever the height and style. the graph for output followed that they provide for 61uw/cm2 to insure plants are not harmed, and then program a timer for output duration.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> the LED has a 120 degree view angle
> 
> now i just need the manufacturer to answer.... the sad part of this is EACH led is $140.





Pumilo said:


> Could it be made as a "mobile" unit, and would it's output be sufficient to do the once a week or once every other week, for an hour or two, method? If so, that $140 would still be cheaper to put one unit together that you could move viv to viv, than it would be to try to buy UV systems for every viv or even the cost of modifying a few vivs with special, UV friendly glass or acrylic.


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## motydesign

well application with UV LED will require a hole in the top of the viv. the emmiter then can be sealed into place to allow for a fly tight application.

damn it doug was on a phone call while typing this so you beat me to it hahah


however, talking with Ed, this really needs to be a constant in the tank, same time same day every day. SOOO to combat that looking at fiber optics for multiple tanks  (its cheaper than multiple LEDs, but output needs to be great enough to support this idea, which is still unproven. and a device like this is REALLY needed to design the system) 
https://secure.mightexsystems.com/pdfs/Mightex_HRS_spectrometer_specifications_Oct2011.pdf


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## Pumilo

motydesign said:


> well application with UV LED will require a hole in the top of the viv. the emmiter then can be sealed into place to allow for a fly tight application.
> 
> damn it doug was on a phone call while typing this so you beat me to it hahah
> 
> 
> however, talking with Ed, this really needs to be a constant in the tank, same time same day every day. SOOO to combat that looking at fiber optics


Ahh, but you get all the credit bro! I'm glad we've got some good heads working on this one. You and Eds back and forth on this just make me feel stupid!


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## Ed

parkanz2 said:


> Have you thought much about mounting techniques for UVB LEDs when we finally get them? If you can get lenses for them (assuming the lenses don't filter out a significant amount of the desired wavelengths,) and they don't run too hot, I'd wonder if you could actually mount the LED so it protrudes through the canopy material which would eliminate filtering of UVB by various materials and the need for gaps/holes allowing fruit fly escapes.
> 
> Getting a bit ahead of things since we don't actually have access to any UVB producing LEDs but one can dream.


The comment on lenses triggered an association in my brain... With respect to some species (like spray toads), institutions have been using halogen track bulbs with the lenses removed to supply UVB to the animals. 

You are correct a small hole can be drilled to supply the passage of the LED. The risk is whether not the UVB can tolerate the moisture that is likely to entail (or actual occasional wetting). It is possible to make a simple mount using acrylic glue (like weld on 16) and a plastic riser tube or piece of PVC which can extend into the tank to control the resulting cone of exposure and protect the LED. 

Ed


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## motydesign

Ed, in my research i have found all emitters are hermetically sealed unless you specify other wise. also i think that the addition of a lens is un needed(view angle can be picked between 7,10, and 120 degrees) and depending on material the lens could possibly filter UV.


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## parkanz2

Have you looked into the transmission of UVB through fiberoptic cable Motydesign? That's a very interesting idea.

Ed, can you possibly PM me some examples of the halogen bulbs you're speaking of? I've heard of this before but haven't seen much info. I'd also be unlikely to actually attempt it without a radiometer.


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## motydesign

Max, yes i have looked into the FO and it seems as if it is standard for carrying UV light. the problem is of course output.if the unit is only capable of enough to do one viv then it is not possible to amplify the UV for multiple FO travelers.


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## bbrock

bobrez said:


> I belive thats 92% uva and 0% uvb for solacryl so holes are nessary for any transmitence. IDK but thats what it looks like.


Hi guys,

I haven't posted here in a LONG time but Ed pointed me to this thread. I confess I'm having a hard time following where some of the numbers come from but it looks like there is an impression that Solacryl transmits UVA but not UVB. If that's what people are thinking, it is an error. Back in 2001 I tested a piece of Solacryl on a high precision spectrophotometer and posted the results on frognet. In 2004, I posted the results on DB. (http://www.dendroboard.com/forum/parts-construction/63732-clay-substrate-how-5.html#post559953 )

The upshot is that Solacryl has very high UV transmittance from visiible to UVB and then becomes opaque to UVC. This makes sense because Solacryl is marketed for tanning beds which wouldn't work very well if it were blocking UVB radiation. It als makes it very handy for filtering light from halogen bulbs since I've read that UVC may be emmitted by an unshielded bulb. So if you grind the the glass filter off a halogen bulb, placing a piece of Solacryl between the bulb and animals may be a prudent safeguard to insure you aren't exposing critters to harmful UVC. I believe I still have the original printout from the test if anyone is interested in the actual numbers.


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## parkanz2

Thanks for the post Brent. I'm excited because it can also be thermoformed... time to get out my old hot wire and get creative.


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## Pumilo

Question for those using Solacryl. How do you get around the problems of bonding it to a glass viv or are you simply using all acrylic vivs?


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## parkanz2

Pumilo said:


> Question for those using Solacryl. How do you get around the problems of bonding it to a glass viv or are you simply using all acrylic vivs?


I just plan on using it for the tops and having it clip into the lip on aquariums or in a track. Are you thinking of sealing it so it will hold water as in the front of a tank?


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## Ed

Pumilo said:


> Question for those using Solacryl. How do you get around the problems of bonding it to a glass viv or are you simply using all acrylic vivs?


You can bond it to the black plastic trim using weldon 16 but I think you can use weld on 40 to bond it to the glass. 

Ed


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## Pumilo

parkanz2 said:


> I just plan on using it for the tops and having it clip into the lip on aquariums or in a track. Are you thinking of sealing it so it will hold water as in the front of a tank?


My vivs are all custom, with no plastic trims. Some sort of track might work ok but Eds suggestion of Weld On 40 would probably do the trick. A little low on shear strength when used on glass but probably plenty of grab for this use.


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## mcaiger53

? for montydesign
I was wondering where you are finding the fiber optic's for transmitting uv? I have been looking into it a bit now and every supplier I have found says that it doesn't transmitt UV, IR, or heat among other things. also that the cladding can be damaged by uv, thus reducing its ability to reflect/refract light through its core. I would be interested in working w it, if its not too expensive. I'm working on designing a diy led powered fiber optic setup for a 180vert. 
Thanks, mike


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## Ed

Pumilo said:


> My vivs are all custom, with no plastic trims. Some sort of track might work ok but Eds suggestion of Weld On 40 would probably do the trick. A little low on shear strength when used on glass but probably plenty of grab for this use.



Just don't pick it up by the top... 

Ed


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## motydesign

mcaiger53 said:


> ? for montydesign
> I was wondering where you are finding the fiber optic's for transmitting uv? I have been looking into it a bit now and every supplier I have found says that it doesn't transmitt UV, IR, or heat among other things. also that the cladding can be damaged by uv, thus reducing its ability to reflect/refract light through its core. I would be interested in working w it, if its not too expensive. I'm working on designing a diy led powered fiber optic setup for a 180vert.
> Thanks, mike



here is one supplier
Polymicro Technologies > Products and Technologies > Capillary Tubing > Flexible Fused Silica Capillary Tubing, TSP: Standard Polyimide Coating, TSG: High Temperature Polyimide Coating, TSU: UV Transparent Coating

problem comes from the focusing that the FO requires...but that could be over come with higher out put


here is a coupled source
Mightex Systems

what i have been looking to find is a LED in a wide band UVA UVB (295-400nm) (will actually have to be a custom order thing)... then you could install it into a coupled source and then feed to tanks... in theory, not sure if its practical yet?
let me know what else you need.... im if your willing to test im willing to listen


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## Ed

People keep concentrating down to the narrow spectrum.. we should keep in mind that a wider range is better for the frogs. 

Ed


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## bbrock

I dug up the old Solacryl test results and scanned them (attached). In the old post I linked to, I was reporting from memory but these are the actual results. About 93% transmission of light from visible through UVA, tapering from ~90% to ~72% through the UVB range, and then rapidly dropping to zero as you cross into UVC.

Using Solacryl can be tricky just like any acrylic glazing. Large panels will warp if exposed to high heat. It doesn't stick well to glass. That combination can be disaster if you don't engineer the top correctly. Just follow the advice of the acrylic experts on the forums. I haven't updated this site in MANY years, but there is a small how-to article on bending Solacryl to make light shields on my old web site: Brock's Vivaria. I'm not saying it is the best way to do it, or even a very good way. But it gives an example of something that worked. For my next round of vivs I plan to use Solacryl mounted in tracks or removable aluminum frames so the panels can be easily replaced when they eventually yellow and check from long term exposure to UVB. Just make sure they are mounted rigidly enough that gaps don't form if the panel tries to warp.


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## motydesign

Ed said:


> People keep concentrating down to the narrow spectrum.. we should keep in mind that a wider range is better for the frogs.
> 
> Ed


Ed are you saying 295-400 is too narrow??? Or is this comment for others?


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## Pumilo

Hey Brent, as someone who has been working with Solacryl for years, what are your thoughts on replacement? I have seen it mentioned a couple of times that it has to be replaced every two years. You mentioned replacement when it turns yellow and checks (tiny cracks). Does this mean it will continue to transmit good amounts of UVB until it begins yellowing? In your experience, how long do you get out of it? Replacement every 2 years is, well, unappealing.


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## bbrock

Pumilo said:


> Hey Brent, as someone who has been working with Solacryl for years, what are your thoughts on replacement? I have seen it mentioned a couple of times that it has to be replaced every two years. You mentioned replacement when it turns yellow and checks (tiny cracks). Does this mean it will continue to transmit good amounts of UVB until it begins yellowing? In your experience, how long do you get out of it? Replacement every 2 years is, well, unappealing.


This is a good question and difficult to answer without data I think. I have always been a little skeptical of the recommendations to replace Solacryl every two years. I think that recommendation comes from the tanning bed industry and probably from people who want to sell Solacryl. I don't replace Solacryl every two years. In fact, I've only replaced it on one viv one time. That sheet had visibly yellowed and checked (after 7 years of use). It's hard for me to imagine that Solacryl would age in a way that would make it opaque to only UV light and not visible. In other words, I think it is the yellowing that reduces performance but that is only conjecture. Unfortunately I no longer have access to a fancy photospectrometer. Before long I hope to purchase a Solarmeter so I can take direct measurements. Without that, I think it is just guesswork.


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## Ed

bbrock said:


> This is a good question and difficult to answer without data I think. I have always been a little skeptical of the recommendations to replace Solacryl every two years. I think that recommendation comes from the tanning bed industry and probably from people who want to sell Solacryl. I don't replace Solacryl every two years. In fact, I've only replaced it on one viv one time. That sheet had visibly yellowed and checked (after 7 years of use). It's hard for me to imagine that Solacryl would age in a way that would make it opaque to only UV light and not visible. In other words, I think it is the yellowing that reduces performance but that is only conjecture. Unfortunately I no longer have access to a fancy photospectrometer. Before long I hope to purchase a Solarmeter so I can take direct measurements. Without that, I think it is just guesswork.


 
I can report that I know that more than one institution replaced it after ten years or so...

Ed


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## motydesign

Brent,
since youve used a true spectrometer, and were able to see the levels for each nm, maybe you can explain the lesser priced solarmeter which just provideds an index. i feel a TON of information is lost between the two units and may provide a false ok for other hobbiest. Being you have seen what bulbs produce what in your viv and at the different heights, that you are able to only now need to do monthly or so checks for intensities to monitor bulb replacements, but what do you think is the best option for people that are just setting up UV in the vivs?


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## Ed

Check out A comparison of responses by three broadband radiometers to different ultraviolet-B sources - Gehrmann - 2004 - Zoo Biology - Wiley Online Library unfortunately I was unable to track down a free copy. It discusses the issues with some of the broadband meters and how they can provide false readings. 

You may also be interested in 
http://www.solarmeter.com/pdfs/paper3.pdf


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## motydesign

Thank you Ed this validifies my ideas with the whole concept. in order to actually know TRUELY what is going on, we need a calibrated spectrometer...


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## bbrock

motydesign said:


> Brent,
> since youve used a true spectrometer, and were able to see the levels for each nm, maybe you can explain the lesser priced solarmeter which just provideds an index. i feel a TON of information is lost between the two units and may provide a false ok for other hobbiest. Being you have seen what bulbs produce what in your viv and at the different heights, that you are able to only now need to do monthly or so checks for intensities to monitor bulb replacements, but what do you think is the best option for people that are just setting up UV in the vivs?


This is something I'm still trying to figure out. First, let me clarify what I have used. I used a spectrometer to measure the transmissivity of Solacryl and also a piece of acrylic I picked up at the local HD (and verified that it blocks almost all UVA and UVB). This was a large bench unit without a portable probe. For measuring light levels in vivs, I have used a LiCor septometer set to record photosynthetically active radiation (PAR) at the tip. That measured how much light that could be used by plants was striking a particular spot in a viv but didn't break down that light by wavelength other than limiting measurements to within PAR. So I haven't ever had my hands on a device that could measure UV in a viv.

Bear in mind that I'm still researching the latest UV meters myself so am not an expert. Solartech offers a variety of units that measure and report different things: Welcome to Solartech. The UV meter group uses mainly the 6.2 which measures UVB and reports the measurement in microwatts/square cm. The 6.4 reports D3 IU/minute. To me, using the 6.2 makes sense since you are recording the UVB energy measured by the unit rather than some calculated index which requires assumptions about whether that index translates to reptile/amphibian use. But sensors in meters vary in their sensitivity response curves so not only do the meters differ in the band width they measure, but also to peaks within that bandwidth. So two lamps that produce the same level of usable UVB might test different if one bulb produces a peak at the meter's band of maximum sensitivity while the other produces a peak off that max sensitivity. But at least we are getting some quantifiable measurement.

What I have done up to this point is use the size of my viv and the manufacturer's stated distance from bulb of producing a therapeutic dose as guidance. Of course you have to trust the manufacturer but I choose a bulb that will throw a therapeutic dose at least 2/3 of the distance from top to floor of viv but ideally to reach just to the floor and not much further. I count on vegetation to block and filter the UVB to create a patchy mosaic of UVB within the viv. I have my UVB bulbs on the same timer as other bulbs so they are on all day. There's a lot of guesswork in that approach but it seems to work. But with a meter in hand, I would definitely combine measurements with the dosing info that Ed has been digging up to adjust intensity and duration with a little more confidence.


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## parkanz2

Are most bulb manufactures compliant when it comes to providing emission data? If you can get that data for a new bulb a meter still seems valuable even if you can't measure the energy of all wavelengths as with a photospectrometer. You could at the very least monitor the decay of the bulb as well as the penetration into the viv. This is assuming you can trust the manufacturer which is a different issue I suppose.

I still need to read more about the different meter models but I've been leaning towards the solarmeter 6.2 as well but as far as monitoring lamp degradation I wonder about the 5.7 model for a UVA + UVB reading as it's been shown that UVA is also involved in vit D3 physiology.


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## motydesign

i agree with everyone, however the 6.2 i feel isnt as useful unless you have a understanding of what your light is producing and create a bench mark to work from. let me see if i can describe my theory of how i think this needs to be done if it were going to be done correctly.

a spectrometer capable of 290-400nm is required at time of bulb install (you will need to use the same bulb every time you replace for bench marking to work... this also assumes that manufacturing will stay with in specifications) you will then also need your 6.2 meter. 

once all materials are procured you can install and turn on the bulb (allow warm up of mercury vapor) and then take measurements with the spectrometer finding what wavelengths your light is producing and at what intensities, then record it. this is for the hobbiest understanding of what they are dosing (each set up will be slightly different depending on how the viv was set up( solacryl, saran, open hole...). this is needed as the 6.2 only measures the 295~nm length which leaves out all info of UVA or any other gradient. so now that you know what you are really dosing the 6.2 can be used to start your bench mark. this 6.2 measurement now needs to be recorded. 6 months later the spectrometer needs to check what you are producing once again and record it then measure with the 6.2 the more you can do this in between the more accurate your bench marking will be. i may have an incorrect thought process here but my hypothesis is different nms will decay at different rates and this will NOT be recorded in the 6.2 since it is measuring such a narrow band.

at this time you no longer need the spectrometer


PLEASE feel free to correct me if there is error in my theory . this is my idea on the correct application and do not assume that is 100% correct.


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## parkanz2

It makes perfect sense Motydesign. The only problem is that very few hobbiests, if any, aren't going to want to buy a 5.7, 6.2 and a spectrometer. Can we settle for one piece of equipment and infer other information from that data based on manufacturer specifications?


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## motydesign

first of all i never said all three devices were needed... just the two expensive ones 

unfortunately no... i have never seen data on decay  of the spectrum just initial output (and i have always questioned how much of that was real until that article Ed posted of side by side testing)(but even this did not test what i am suggesting)

the 5.7 i feel isnt as useful to us as the 6.2 would be after a bench mark was created.

some one needs to bite the bullet or at least have a unit available to borrow for a bit.

this is what we need for each light we want to use (this is an example not an actual reading of UV light)


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## ckays

I wonder how much of this testing has already been performed. 

Have you look into the UVB Meter Group @

UVB_Meter_Owners

It's yahoo group that I have been subscribed to for years now. I stopped going through the data a very long time ago (my needs were met) I will go back through all of the "newsletters" over the next few days to see if I find anything pertinent. 

I would bet that much of this testing has already been performed I'll start digging.


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## parkanz2

That would be great Ckays. Hopefully uvguide.co.uk gets their data back up soon as well, it seems like he does a very thorough job.


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