# UV Benefits or not?



## kyle1745 (Feb 15, 2004)

Lately I have been thinking to replace half of my lights with UV bulbs.

I had read years ago that almost no UV makes it through the glass in the tanks, but my thinking is that even is some does it is better than none. Granted if it is beneficial... So thus why im posting it in the Science section.

Does enough UV make it though common glass to make a UV bulb worth it? Do the frogs benefit? or is that debatable?


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## Ed (Sep 19, 2004)

If you are looking to add UVB to the tank then no. If you are intending to add UVA as this may enhance behaviors then probably yes. 

Window glass absorbs the UVB portion of the spectrum while passing through the UVA section (See http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Citation )

Ed


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## r90s (Jun 13, 2006)

Kyle,

I use OP4 plexi-Glass (acrylic) for Lids. Plexi does not block UV as badly as glass, and OP4 is made to pass the maximum amount of UV.

However, using plexi requires bracing to prevent warping.


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## kyle1745 (Feb 15, 2004)

There used to be a site that broke down how much UV made it through the glass in tanks, and it seems to be gone.

So are the benefits worth it for the 3x the price in lights? My thinking was, as with most things even if they got a little bit it would be better than none at all. Doesn't UV also help keep bacteria in check?


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## Dancing frogs (Feb 20, 2004)

I have a few tanks that are completely outfitted for UV (including OP-4 or solacryl tops)...but can't say one way or another if I am seeing benefits, as there is no "control" group to compare to.
For UV light bulbs, it really pays to shop around.


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## kyle1745 (Feb 15, 2004)

Any suggestions?


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## Ed (Sep 19, 2004)

Kyle,

It goes back to my point... Are you looking to increase UVB exposure or UVA exposure or both? 

Ed


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## kyle1745 (Feb 15, 2004)

It seems like UVA is possible and UVB is not, as I do not have an easy way to put lights in the tanks. 

So I guess my answer is I am not sure. I was just thinking the other day as I have had to recently replace some bulbs, that maybe some UV bulbs wouldn't hurt. I know there has been much debate on if the frogs benefit from it or not.


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## zaroba (Apr 8, 2006)

in the wild don't darts live in the shade of trees and on the ground where no UV light would reach anyway? so how would it benifit one?

plants however, i've seen sites that tested plants with and without uv light. the ones without it looked much worse then the ones that got tons of it.


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## kyle1745 (Feb 15, 2004)

Yes but there have been some that say they do get sun exposure, but when they want it.

Did you happen to note what type of UV benefited the plants?


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## Ed (Sep 19, 2004)

All because an animal is in the shade does not mean that it is not being exposed to UV lighting.. keep in mind that UV light can refract and reflect which is why simply being in the shade doesn't mean that they aren't exposed or that they can't benefit from UV exposure. 

There has been at least one study that shows that shade dwelling lizards can synthesize D3 from less UVB exposure.. 

see http://www.ncbi.nlm.nih.gov/entrez/quer ... t=Abstract 

Typically what I would say is that UVB is used for calcium metabolism and is a good backup sysytem if there is insufficent D3 in the diet (as the frog will not make more D3 unless there is an insufficiency). With respect to UVA, there hasn't been a lot of studies on its use in anurans but with lizards, insects and birds it has a lot of use for behavioral issues and potentially feeding. I would suspect (as it used this way in birds and reptiles) that it can play a significant part in the recognition of prey items as many insects have reflective patterns in the UVA spectra. 


Ed


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## rmelancon (Apr 5, 2004)

So assuming UVB doesn't make it through the glass and UVA does (which is what I have gathered so far)... a bulb like the following:

"The Reptile Super UV Daylight Fluorescent Lamp is a full-spectrum daylight lamp that produces beneficial ultraviolet rays, 3%+ UVB and 7%+ UVA, which help process calcium for bone growth..."

Would provide some UVA which may or may not be beneficial, correct? Is it safe to assume that worst case it would provide no benefits but at least not be harmful?

Another question: using the same bulb on a "screen" top tank, both UVA and UVB would make it through, which I gather for dendrobatids would potentially be a good thing?

Final question: would there be any risk of over exposure as they would not be able to escape it in a tank environment.


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## Ed (Sep 19, 2004)

Hi Rob,

I have snipped and pasted to answer each question. 

snip ""The Reptile Super UV Daylight Fluorescent Lamp is a full-spectrum daylight lamp that produces beneficial ultraviolet rays, 3%+ UVB and 7%+ UVA, which help process calcium for bone growth..." 

Would provide some UVA which may or may not be beneficial, correct? Is it safe to assume that worst case it would provide no benefits but at least not be harmful? "endsnip

There are records of overexposure to UV light bulbs (see Biomedical and Surgical Aspects of Reptile Husbandry for the details) but most of those involved lamps that produce large amounts of UV lighting. With respect to the bulb listed above, the amount of UVA is small, and really doesn't provide much in the way of any benefit at distances greater than 18 inches.... In addition if there are hide areas that shelter the frog (like coco huts, dry leaves) the frogs will also regulate thier exposure. 


snip "Another question: using the same bulb on a "screen" top tank, both UVA and UVB would make it through, which I gather for dendrobatids would potentially be a good thing? "endsnip

There is less penetration of the UV due to the interference of the screen but there is some penetration. Again, once you get past 18 inches the effectiveness of the lights is really minimal (close to 0). Ideally the exposure distance won't be greater than 10-12 inches. 


Ed


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## kyle1745 (Feb 15, 2004)

I did notice while looking at bulbs that some claim 20 inch exposure. Granted not a lot more.


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## Dancing frogs (Feb 20, 2004)

http://www.reptilesdownunder.com/reptil ... testsa.php
I thought I also had a link in my favorites showing UV transparency, but can't seem to find it at the moment.
I'm not so sure on the UV output of the desert 7% bulbs...one test showed the normal flourescent version of that bulb had very little UVB...so I have to wonder how good the PC version is, though at present they are the only ones to offer a high output flourescent source of UV.

From what I have seen, most reptile keepers that keep things that actually are proven to do better with UV stick with the 5.0 bulbs, or the new 10.0 by the same manufacturer.

For Reptisun 5.0, the best price I've found is ...something like $13 a bulb, for any size, what I don't like is that any of them over 18" long is a T-12 bulb.


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## stchupa (Apr 25, 2006)

Just to answer the :?: the topic gives. Hmmm, nonetheless in an obvious way.

If a certain aspect (all) are present in the animals' natural habitat, one way or another/ directly/indirectly, it will be taken advantage/made use of. Contributing to a greater capacity to w/stand various alterations (shock both of/ w/in the environment/ the animal itself), and the continuation to change along w/. "Common" 'sense' would say there's a limit, so a little less than what can be used is better than to much (especially w/in 'our' artificially handed provisions), but 'some' is surely beneficial. 
You have to consider other/all things, not just the frog(s) that share the same habitat, everything supporting another (indirectly['directly]). So say if the frog is incapable of utilizing these wavelengths directly (not saying they don't), the 'things' it eats (arthropods) do, and the things those 'things' eat do as well (plants/other orgs that CAN absorb/convert it). So I will but shouldn't have to say that this would need to be recreated in 'our' applications to get a similar result. That is to say you maintain a mi eco artificially. Soma do, some don't, but all should.

I can't remember for sure but I thought most acrylics/plastics blocked out more UVA/B... than glass?

I can give a great example in an unrelated way of UV importance.
Mantids are the best example as far as the advances in health it gives when compared to a situation where it is less or not present. Many might not think or realize that such a creature would have use for this. In the main scheme of things, growth (which is 'most' everyone's basic focus in determining health), it is not necessarily required to give the same overall girth. But when you compare the two example, the first most strikingly evident comparison is the color, it's obvious one looks much healthier than the other, you can probably guess which. Then the most important (imo) noticeable difference is the physical response change that occurs in the deprived specimen. It's actually a neuro malformation that is seen as/in a physical way, that is what conducts it. Energy to help things work/absorb/assimilate/grow more efficiently is obviously devoid in that example. The difference is profound when elapsing time in observation. I think the same would go for most things, including frogs. The heat generated by the waves plays just as an important role w/ this creature as absorbing the actual rays, so that's where the comparison w/ a pdf would end. But that aside if it's there, always been there, it needs to stay there (UV).

Is A longer than B? That's an important thing to remember and I should know that for sure. I 'think' it is.


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## stchupa (Apr 25, 2006)

zaroba said:


> in the wild don't darts live in the shade of trees and on the ground where no UV light would reach anyway? so how would it benifit one?


People that go out hunting/observing usually have a trained position of taking a full view before taking the first step. That's how they get the chance to get a less influenced observation of behavior.

Many if not all darts will take the chance, if given, to get out in the open to bathe. This is only observable in a situation where there tends to be open ground (at 'our' level), and when they are not aware of your presence, otherwise they'll tend to hide more frequently.

Now consider a heavily forested area w/ no opening in the canopy/over growth. Chances are (in many/most cases) the points of interest to the frog(s) are not at an easily observable/accessible level. So many of these frogs may be basking high in the canopy where many of their offspring are tended as well. Just because 'you' don't see it doesn't mean it's not happening. 'You're' much more limited than they are and if they have the chance of taking a level 'you're' less likely intrude on, they'll probably have the preference of taking advantage of it.


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## r90s (Jun 13, 2006)

Some Links that may provide info that helps.

http://www.uvguide.co.uk/ ------Note tabs, left side of page.

http://www.doylesdartden.com/lighting.htm#Do Amphibians Require Special Light

http://www.reeflightinginfo.arvixe.com/

ps: whats the deal with url problem?


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## Dancing frogs (Feb 20, 2004)

Thanks for posting those links...good stuff!


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## Ed (Sep 19, 2004)

snip "I'm not so sure on the UV output of the desert 7% bulbs...one test showed the normal flourescent version of that bulb had very little UVB...so I have to wonder how good the PC version is, though at present they are the only ones to offer a high output flourescent source of UV"endsnip

There was a recent paper (I have a copy but can't lay my hands on it at the moment) that (if I remember correctly) demonstrated that a lot of UV meters people are using to detect the levels of UVB are not calibrated for this purpose and maybe thrown off by background or other interference.
(They compared to the detection to the known rate of photoconversion of pre-vitamin D3 to D3 in quartz vials versus the amount of UVB detected with the different meters as well as by meters calibrated to specifically detect UVB..) (I'll post the reference later) 

So a number of the tests done on the bulbs maybe inaccurate.. depending on the meter used and the methodology used... 

Ed


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## r90s (Jun 13, 2006)

Thanks for pointing that out ED, its been a while since I looked over this and other ultraviolet info, but I do recall that.

When I have time I will look at my stored web pages, and papers, and will also post anything appropriate that I find.

I did not re-examine the links I posted to check on meter sensors used, and appropriate calibration, but recall that some I looked at in the past did take this factor into account. They used either separate sensors, or a broadband sensor.


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## rmelancon (Apr 5, 2004)

Thanks for the answers Ed.

The tanks I'm thinking about putting these on are less than 18 inches tall to begin with, then you can subtract a few more inches for substrate etc. I figure the average distance from light to ground would be around 12-15 inches. There's been a lot of talk in the past about UV and blue jeans pumilio, I guess I'll give it a shot and see if I notice any difference in behavior etc.


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## kyle1745 (Feb 15, 2004)

Yes I have read many of those links, but long ago. If I remember correctly the one link I had been looking for was where much of the information on Doyles site came from, but the info is no longer there.

Ill have to find some time to go read them all again.


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## Ed (Sep 19, 2004)

snip "I did not re-examine the links I posted to check on meter sensors used, and appropriate calibration, but recall that some I looked at in the past did take this factor into account. They used either separate sensors, or a broadband sensor."endsnip 

From the reference I had in mind 

quote "Hand-held broad band radiometers are less expensive and easier to use but may indicate irradiances that are significantly different from actual values. Gehrmann et al (2004) examined three different types of broadband radiometers and showed that the meters indicate different levels of irradiance from the same light source." endquote 

from Gehrmann, W.H.; Jamison, D.; Ferguson, G.W.; Horner, J.D.; Chen, T.C.; 2004; A comparison fo vitamin D-synthesizing ability of different light sources to irradiances measured with a Solarmeter Model 6.2 UVB meter; Herpetological Review 35(4): 361-364

The same article indicates that the ESU Reptile Desert 7% UVB does indeed produce UVB and data extrapolated from a study with Furcifer pardalis indicates that the most effective distance for this bulb is between about 11 cm (4.3 inches) to 20 cm (7.9 inches) produces sufficient UVB to allow for sufficient photoconversion of pro-vitamin D3 to D3. 
And the Reptisun 5.0 should be between the same distances to be effective.. 


Ed


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## bbrock (May 20, 2004)

I have posted extensively about UVA/UVB in dart frogs both on this forum and on frognet in the past. I'm not going to rehash those posts but will say that I think it is a waste of time to supply UV light (either A or B) without making sure you have a UV transparent glazing. The old link I think people are remembering about the transmisivity of various glazing materials was crap and I wouldn't trust it. The problem is that these tests are typically done on a single sample of glazing. For example, that test indicated that 1/8" plexiglass transmitted most of the UVA and something like 70% of the UVB shined through it. That may be true for that particular sample but it can't be assumed that all 1/8" acrylic will perform the same. I tested a piece of acrylic picked up at a local home improvement store on a spectrometer and found that all UVB and more than 90% of the UVA was actually blocked. I was told by someone in the plastics industry that acrylic intended for window glazing typically includes UV inhibitors to prolong the life of the plastic. I then tested a piece of Solacryl which transmits almost all UVA and UVB but no UVC as advertised. The same goes for window glass. Some window glass can transmit UVA which is why curtains and carpets fade when light shines through the window. But the glass can be formulated to block all of the UV light. Therefore, the smart thing to assume is that a piece of glazing will block most UV unless you choose a glazing that you are certain will transmit.


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## rmelancon (Apr 5, 2004)

In my case the only thing blocking the UV will be a thin mesh material. I'll have to look into a good UV meter, anyone have links for these?


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## Ed (Sep 19, 2004)

Hi Rob,

I can get you the citation from the above article where they rated the different meters but that is about all I can do at this point. 

Ed


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## Dancing frogs (Feb 20, 2004)

Don't know how good it is, but this is the only one I could find (last I looked) that was cheap enough to consider buying.
Anyway here is the unit:

http://www.professionalequipment.com/xq ... efault.htm


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## Dancing frogs (Feb 20, 2004)

Anyone have a ballpark idea what it would cost to do the D3 conversion test for UV?
I would think that would be the most useful reading.


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