# Necessary to have fans?



## Venomgland (Dec 31, 2017)

I've been seeing that people use computer fans in there vivariums for air flow. How necessary is this? Is it more for the plants or the frogs? I'm still learning.


----------



## Encyclia (Aug 23, 2013)

In most cases, they aren't 100% necessary. It really depends on how your ventilation works. Exos and ZooMeds come with vents under the doors and at the top so they are fairly good at passive ventilation. If you have a converted aquarium that only opens at the top, that is the kind of situation where a fan could help. It's tough to get good passive ventilation in that setup. Having said all of that, I don't regret putting fans in any of the tanks I have them in.

It can be for the frogs and the plants. For the frogs, you want to maintain about 60-80% humidity, NOT 100%. Old school frog vivs used to be completely sealed. That is no good. 100% humidity keeps frogs from being able to cool themselves evaporatively. Some plants like to be able to dry out between mistings, too, so having a fan can help that situation. 

Be advised, though, that keeping the proper humidity (and temperature) is a function of your ventilation and the outside temperature and humidity. A misplaced fan or one that runs too long/often can dry your tank out quite a bit. You may need to experiment to achieve a balance between getting rid of condensation on the glass (one of the most obvious fan benefits) and drying your tank out too much. 

Best of luck,

Mark


----------



## Ibn (Aug 3, 2016)

Encyclia said:


> In most cases, they aren't 100% necessary. It really depends on how your ventilation works. Exos and ZooMeds come with vents under the doors and at the top so they are fairly good at passive ventilation. If you have a converted aquarium that only opens at the top, that is the kind of situation where a fan could help. It's tough to get good passive ventilation in that setup. Having said all of that, I don't regret putting fans in any of the tanks I have them in.
> 
> It can be for the frogs and the plants. For the frogs, you want to maintain about 60-80% humidity, NOT 100%. Old school frog vivs used to be completely sealed. That is no good. 100% humidity keeps frogs from being able to cool themselves evaporatively. Some plants like to be able to dry out between mistings, too, so having a fan can help that situation.
> 
> ...


This post succinctly explains it so well on so many levels. It's hard to imagine that a simple question of what kind of humidity is required for darts, and to a lesser degree plants, could be so hard to find the answer to. 

I've been using a couple of external fans (on low setting) to pull air out of the viv through the mesh top of the Biopod to drop levels back down to within the 60-80% range. They've been running for about 14 hours now and my humidity has steadied itself in the 78-84% range depending on when the misters kick in. The plants looked better this morning versus the past few days when humidity was in the 94-96% range.


----------



## Venomgland (Dec 31, 2017)

Great information! Thanks!


----------



## braydens (Sep 13, 2011)

Ive kept tree frogs for a number of years (red eyes, tiger leg, whites) and have found they do a lot better with air circulation. I should mention this is with a 2" vent. i have air blowing in through the vent and within (depending on tank size)


----------



## Encyclia (Aug 23, 2013)

braydens said:


> Ive kept tree frogs for a number of years (red eyes, tiger leg, whites) and have found they do a lot better with air circulation. I should mention this is with a 2" vent. i have air blowing in through the vent and within (depending on tank size)


This speaks to how complex this situation is. This works great for braydens, but if I was to use this method, I would dry my vivs out in a heartbeat. I have larger vents and I try to position my fans so that I get a mixture of outside air coming in and inside air recirculating. My outside air is too dry to do what braydens does. I might be able to do it if I used a seconds timer to only have the fans on a few seconds each hour (for example; I am not saying this is the right amount for anyone), but if they were on constantly in that configuration, I would kill all of my plants, then the frogs. If you go with a fan, plan on spending some time monitoring the situation to make sure the humidity isn't dropping too low or staying too high. Move the fans or put them on a timer if you are getting wide swings in humidity. 

Mark


----------



## Pumilo (Sep 4, 2010)

It's not completely necessary, but without fans in your viv, your froggies will have a much harder time launching their rock band into super-stardom.


----------



## Pumilo (Sep 4, 2010)

Seriously though, fans are a great tool, but not totally necessary. The proper use of passive ventilation is a much more useful tool. In my opinion, passive ventilation should be required in our hobby. Both your frogs, and your plants, will benefit from passive ventilation.

Proper implementation of passive ventilation entails the use of 2 vents. One at the bottom, and one at the top. Adding that second vent does not make your system twice as effective. It makes it many times more effective. Here is an explanation I wrote up on FaceBook late last night. 
_
"Invert a full gallon of water from a milk style jug. It goes glug...glug...glug... Every pause between glugs, is time that water is not flowing properly. While it's still draining, pop a hole in the base of the jug with a knife, and twist. Air now flows freely into the jug. The glugging stops, and the jug pours several times faster than before. As already mentioned, hot air rises, and that's what we want to remove. Not just any air, but hot air. The hot air already wants to leave through the vent, but if you only have a top vent, the viv cannot properly displace the hot air that is leaving. The viv cannot breathe, so air does not exit efficiently. It needs to breathe in. Putting the bottom vent in, allows the viv to breathe fresh air in, while simultaneously breathing hot air, out. Putting a bottom vent in, combined with an upper vent, makes your ventilation much more effective and efficient. Now that you have air going out, at the top, and air coming in, at the bottom, you have actually created a very slight breeze in your vivarium, sort of a convection current, and that is a very good thing. An internal circulation fan is nice, and very helpful for certain plants, like miniature orchids, but establishing proper ventilation through the use of 2 passive vents, is so much more important and helpful."_


----------



## n5td (Jan 16, 2018)

on the exo terra, are the two cord slots plus the bottom vent enough for passive air flow?

Sent from my SM-G930T using Tapatalk


----------



## Encyclia (Aug 23, 2013)

n5td said:


> on the exo terra, are the two cord slots plus the bottom vent enough for passive air flow?
> 
> Sent from my SM-G930T using Tapatalk


I would say no. Since it's passive ventilation, there is not much to "push" the air through a choke point. On all of my Exos, I have a piece of glass that covers all of the top vent except a couple of inches at the back. I usually hot glue some fiberglass screen or no-seeum mesh over this last couple of inches at the back of top. This leads to passive flow from under the doors, diagonally across the tank and up toward the top. Completely sealing the top of an Exo is not going to help your passive air flow. 

Mark


----------



## Andrew Lee (Jan 21, 2014)

Pumilo said:


> _
> "Invert a full gallon of water from a milk style jug. It goes glug...glug...glug... Every pause between glugs, is time that water is not flowing properly. While it's still draining, pop a hole in the base of the jug with a knife, and twist. Air now flows freely into the jug. The glugging stops, and the jug pours several times faster than before. As already mentioned, hot air rises, and that's what we want to remove. Not just any air, but hot air. The hot air already wants to leave through the vent, but if you only have a top vent, the viv cannot properly displace the hot air that is leaving. The viv cannot breathe, so air does not exit efficiently. It needs to breathe in. Putting the bottom vent in, allows the viv to breathe fresh air in, while simultaneously breathing hot air, out. Putting a bottom vent in, combined with an upper vent, makes your ventilation much more effective and efficient. Now that you have air going out, at the top, and air coming in, at the bottom, you have actually created a very slight breeze in your vivarium, sort of a convection current, and that is a very good thing. An internal circulation fan is nice, and very helpful for certain plants, like miniature orchids, but establishing proper ventilation through the use of 2 passive vents, is so much more important and helpful."_


I like that explanation. What would happen if you happened to put two top vents with a fan pushing air through one into the viv and nothing on the other? So basically just a different "bottom vent"


----------



## Andrew Lee (Jan 21, 2014)

Pumilo said:


> _
> "Invert a full gallon of water from a milk style jug. It goes glug...glug...glug... Every pause between glugs, is time that water is not flowing properly. While it's still draining, pop a hole in the base of the jug with a knife, and twist. Air now flows freely into the jug. The glugging stops, and the jug pours several times faster than before. As already mentioned, hot air rises, and that's what we want to remove. Not just any air, but hot air. The hot air already wants to leave through the vent, but if you only have a top vent, the viv cannot properly displace the hot air that is leaving. The viv cannot breathe, so air does not exit efficiently. It needs to breathe in. Putting the bottom vent in, allows the viv to breathe fresh air in, while simultaneously breathing hot air, out. Putting a bottom vent in, combined with an upper vent, makes your ventilation much more effective and efficient. Now that you have air going out, at the top, and air coming in, at the bottom, you have actually created a very slight breeze in your vivarium, sort of a convection current, and that is a very good thing. An internal circulation fan is nice, and very helpful for certain plants, like miniature orchids, but establishing proper ventilation through the use of 2 passive vents, is so much more important and helpful."_


I like that explanation. What would happen if you happened to put two top vents with a fan pushing air through one into the viv and nothing on the other? So basically just a different "bottom vent". Fresh air would enter the viv through the fan and hot air would leave through the passive vent, right?


----------



## jarteta97 (Jun 13, 2014)

Encyclia said:


> I would say no. Since it's passive ventilation, there is not much to "push" the air through a choke point. On all of my Exos, I have a piece of glass that covers all of the top vent except a couple of inches at the back. I usually hot glue some fiberglass screen or no-seeum mesh over this last couple of inches at the back of top. This leads to passive flow from under the doors, diagonally across the tank and up toward the top. Completely sealing the top of an Exo is not going to help your passive air flow.
> 
> Mark


I haven't yet siliconed my top glass piece, but I have the top essentially "ready to assemble" for my new build, with the 3 inch vent already constructed separately. I always figured that having the vent at the front instead of the back would do better at keeping the front glass clear. I understand, though, the benefit of the diagonal cross-breeze if the vent is placed at the back. I just want to know if your front pane of glass still stays clear with this setup? I may put the vent at the back now that I've seen this. 

Another concern I have, though, is whether my upper background plants will still get adequate light with the vent in the way, as it would be if placed in the back. I tend to have fewer plants at the very front of the tank, so the forwards vent doesn't seem to have quite as negative an effect on light distribution as I fear would happen if I had a rear vent. Any thoughts on this Mark?


----------



## n5td (Jan 16, 2018)

jarteta97 said:


> I haven't yet siliconed my top glass piece, but I have the top essentially "ready to assemble" for my new build, with the 3 inch vent already constructed separately. I always figured that having the vent at the front instead of the back would do better at keeping the front glass clear. I understand, though, the benefit of the diagonal cross-breeze if the vent is placed at the back. I just want to know if your front pane of glass still stays clear with this setup? I may put the vent at the back now that I've seen this.
> 
> Another concern I have, though, is whether my upper background plants will still get adequate light with the vent in the way, as it would be if placed in the back. I tend to have fewer plants at the very front of the tank, so the forwards vent doesn't seem to have quite as negative an effect on light distribution as I fear would happen if I had a rear vent. Any thoughts on this Mark?


I have a similar question. Vent in the back, mid, or front?


----------



## Venomgland (Dec 31, 2017)

Pumilo said:


> It's not completely necessary, but without fans in your viv, your froggies will have a much harder time launching their rock band into super-stardom.


You mean like Les Claypool's Fearless Flying Frog Brigade?


----------



## Pumilo (Sep 4, 2010)

Andrew Lee said:


> I like that explanation. What would happen if you happened to put two top vents with a fan pushing air through one into the viv and nothing on the other? So basically just a different "bottom vent". Fresh air would enter the viv through the fan and hot air would leave through the passive vent, right?


True, but it's no longer passive ventilation. It is now powered ventilation, and unless very carefully controlled, could dry things out way too fast. Some have used powered ventilation successfully. I choose not to, and I choose to advise others not to. The reason is because powered ventilation has the potential to exchange too much air, too fast. Here in CO, it's just too dry for me to even consider it for my own uses. I advise other's against it because it needs to be carefully monitored and adjusted to a fine balance. If somebody is techy enough to do it right, more power to you, but please...be careful. It's your frogs that pay the price for overpowered ventilation.

I keep my fans inside the vivarium. They pull air from inside the vivarium, and expel it right back into the vivarium. My fans operate exactly like a fan on the living room floor, simply moving air around the room. I run mine 10 minutes on, and 10 minutes off.

Two passive vents on top of the viv, are still much better than one, but not as good as one up top, and one down low.


----------



## Encyclia (Aug 23, 2013)

jarteta97 said:


> I haven't yet siliconed my top glass piece, but I have the top essentially "ready to assemble" for my new build, with the 3 inch vent already constructed separately. I always figured that having the vent at the front instead of the back would do better at keeping the front glass clear. I understand, though, the benefit of the diagonal cross-breeze if the vent is placed at the back. I just want to know if your front pane of glass still stays clear with this setup? I may put the vent at the back now that I've seen this.
> 
> Another concern I have, though, is whether my upper background plants will still get adequate light with the vent in the way, as it would be if placed in the back. I tend to have fewer plants at the very front of the tank, so the forwards vent doesn't seem to have quite as negative an effect on light distribution as I fear would happen if I had a rear vent. Any thoughts on this Mark?


This is a good question. I have some tanks that have sort of mid- to front vents (pumilo built them, as a matter of fact . In these tanks, I get less condensation and I think the passive ventilation seems to work well for the plants throughout the tank. However, I don't know that this would work as well in a bigger tank (these are smaller than 18x18x24s). In my big tank (36x18x36), I have back vents and it is sometimes a while before my front glass gets clear, but I can turn the fans up a bit if I want to clear the glass. The overall answer might be that you can get away with middle or front vents for passive ventilation in smaller tanks, but that bigger tanks could use that diagonal dynamic that I described earlier. In a big tank, you could get away with a front vent and that would keep the condensation in check better, but I think you would really decrease your passive ventilation to the rest of the tank. I would rather have the whole tank ventilated properly and deal with a little bit of condensation in the mornings.

To make sure that we are comparing apples to apples, I will say that I also have recirculating fans in my big tank. Because of where they are positioned (suction cupped to the "roof" at the back next to the vent), they are also pulling in air from outside, though I am not sure it is all that much. Because of this positioning and their angle (down and toward the front of the glass), I am pretty sure that I am messing with the optimal efficiency of the passive ventilation cycle, but overall, it seems to work well. I just want to be clear that there are two kinds of air movement you can have, one that involves air exchange with the outside, and the other that just re-circulates air inside the tank. Both are a factor in how you maintain humidity and in how "comfortable" your frogs and plants are.

Mark


----------



## jarteta97 (Jun 13, 2014)

Thank you for the information, Mark. The tank in question is a 24x18x36, so that diagonal airflow will be more appreciated (at least by the plants) than having clear front glass. I think that I will end up placing the vent in the back, and I'll just play around a little bit with the lighting. Eventually I am going to get an internal circulation fan and place it near the vent (but not too close) as you described. One day I'm hoping to get some miniature orchids for this tank, so that airflow will be much appreciated.


----------



## Encyclia (Aug 23, 2013)

jarteta97 said:


> Thank you for the information, Mark. The tank in question is a 24x18x36, so that diagonal airflow will be more appreciated (at least by the plants) than having clear front glass. I think that I will end up placing the vent in the back, and I'll just play around a little bit with the lighting. Eventually I am going to get an internal circulation fan and place it near the vent (but not too close) as you described. One day I'm hoping to get some miniature orchids for this tank, so that airflow will be much appreciated.


I forgot about the lighting issue. I don't think that's a problem at all. The lightning is not really cut down all that much by mesh (either no-seeum or fiberglass screen) and the area at the top is closest to the light so even though you are a little shaded and off-nadir (the light angle is wider in that spot), you will still get plenty of light, in my experience.

Mark


----------



## jarteta97 (Jun 13, 2014)

Encyclia said:


> I forgot about the lighting issue. I don't think that's a problem at all. The lightning is not really cut down all that much by mesh (either no-seeum or fiberglass screen) and the area at the top is closest to the light so even though you are a little shaded and off-nadir (the light angle is wider in that spot), you will still get plenty of light, in my experience.
> 
> Mark


That's exactly what I was thinking. The plants under the mesh will be way up closer to the light anyways. I figured that even a finnex could get through the no-seeum and down maybe 6 to 12 inches to the upper plants on the background. Heck, it may even prevent the topmost ones from burning.


----------



## Ibn (Aug 3, 2016)

Been mulling over this for the last few days myself and have been experimenting on the Biopod, since acquiring some mini orchids from Doug. 

The Biopod actually has a ventilation system where it pulls air in from the front of the unit with passive mesh in the top front section. With the orchids in the tank, I noticed that the humidity in the tank was sticking in the ~95% range and the leaves were staying wet, which is something that I didn't want. Sticking a fan in the unit was out of the question since it's sealed up relatively well with locking clips on the top lid, and would requiring drilling/modding the top. I didn't want to do this since this would void the warranty on the unit. 

With the above in mind, I decided to test out a couple of fans which would sit on the top mesh and pull air out of the Biopod (pushing air into the unit was out of the question since that would dry it out pretty quickly since the room is relatively dry). A pair of AC infinity 80mm fans were ordered along with a WeMo smart plug. Running both fans on 24/7 drops humidity into the 70s so I've been experimenting by using the WeMo to program the on/off for the fans. 

WeMo programming for on/offs.









I'll be monitoring the dashboard to see how the programming affects the humidity throughout the day as the fans comes on or goes offline.


----------



## n5td (Jan 16, 2018)

Ibn said:


> Been mulling over this for the last few days myself and have been experimenting on the Biopod, since acquiring some mini orchids from Doug.
> 
> The Biopod actually has a ventilation system where it pulls air in from the front of the unit with passive mesh in the top front section. With the orchids in the tank, I noticed that the humidity in the tank was sticking in the ~95% range and the leaves were staying wet, which is something that I didn't want. Sticking a fan in the unit was out of the question since it's sealed up relatively well with locking clips on the top lid, and would requiring drilling/modding the top. I didn't want to do this since this would void the warranty on the unit.
> 
> ...


Do you have pics of the fans positions in the biopod?


----------



## Ibn (Aug 3, 2016)

I don't presently, but they're basically on the edge of the mesh on each side of it for the initial test. I'll be playing around with it by moving them further out though from the looks of things. The fans kicked in at 10 a.m. and it has already dropped the humidity down pretty substantially. The initial high humidity might have just been because the misters went online for 32 seconds (10 minutes before the fans kicked in). I'll be monitoring the levels through the cycle and see what happens.


----------



## serial hobbiest (Mar 5, 2017)

Pumilo said:


> True, but it's no longer passive ventilation. It is now powered ventilation, and unless very carefully controlled, could dry things out way too fast. Some have used powered ventilation successfully. I choose not to, and I choose to advise others not to. The reason is because powered ventilation has the potential to exchange too much air, too fast. Here in CO, it's just too dry for me to even consider it for my own uses. I advise other's against it because it needs to be carefully monitored and adjusted to a fine balance. If somebody is techy enough to do it right, more power to you, but please...be careful. It's your frogs that pay the price for overpowered ventilation.
> 
> I keep my fans inside the vivarium. They pull air from inside the vivarium, and expel it right back into the vivarium. My fans operate exactly like a fan on the living room floor, simply moving air around the room. I run mine 10 minutes on, and 10 minutes off.
> 
> Two passive vents on top of the viv, are still much better than one, but not as good as one up top, and one down low.


I'm in the camp of powered ventilation, and I must ask if you think it may be the ultimate source of the challenges I've been facing. Posting my issues here may illustrate some of the problems this causes for the benefit of the OP. I have a heavily planted 18x18x24 ExoTerra, with a 1.5" no-see-um mesh vent across the back & a 4" muffin fan on top. The fan is about 1/2" to 3/4" above the mesh, so there's a great loss of efficiency in terms of % of air moved by the fan actually making it in to the viv.

After a few months of owning frogs, I noticed that my water layer was gradually going down, indicating more evaporation than what I was replacing with mist. Back then, I was misting less frequently, and running the fan less often, and scratching my head over my relentless mold problem. Well I wasn't about to start misting less when I'm already evaporating more than I'm replacing, so I increased the mist frequency and durations so I could (and by could I mean MUST) run the fan more, so that everything was dripping wet and soggy all the time. So you can see the counter-intuitiveness of my situation. I don't want to mist 6 times a day, but apparently I have to, given that I'm blowing 35% to 40% RH air in on a regular basis. Erring on the side of caution, as to not make frog jerky, the conditions are probably too wet in there, and I say this although my background is mostly dry, & my planters on my background require manual watering, believe it or not, and FYI, my mid-viv/foreground plants barely have time to dry off in between mistings. I'm paranoid to run the fan if the plants are dry, as I'm sure you can understand.

Recently, I've shaved some seconds off of each mist cycle, and observed what I think is a telling behavioral change of my frogs. A few weeks ago, before the change, they would always be hiding in the cork tube that lays on the floor. I had a hunch that perhaps they were there because no direct mist gets inside. I got confirmation of this the day after I made the change. The frogs adopted a new hiding spot up in one of the background planters, now that the plants up there were dry most of the time. A couple days ago, I was a big jerk, and ripped that plant out of their hiding spot, and so they've taken to the cork tube again. 

I'd like to hang an internal fan from the glass top now, and probably get rid of the other one entirely. Can you direct me to a resource for building internal vivarium fans for dummies? The whole electric motors in a misty environment thing has me head scratching.


----------



## Encyclia (Aug 23, 2013)

serial hobbiest said:


> I'm in the camp of powered ventilation, and I must ask if you think it may be the ultimate source of the challenges I've been facing. Posting my issues here may illustrate some of the problems this causes for the benefit of the OP. I have a heavily planted 18x18x24 ExoTerra, with a 1.5" no-see-um mesh vent across the back & a 4" muffin fan on top. The fan is about 1/2" to 3/4" above the mesh, so there's a great loss of efficiency in terms of % of air moved by the fan actually making it in to the viv.
> 
> After a few months of owning frogs, I noticed that my water layer was gradually going down, indicating more evaporation than what I was replacing with mist. Back then, I was misting less frequently, and running the fan less often, and scratching my head over my relentless mold problem. Well I wasn't about to start misting less when I'm already evaporating more than I'm replacing, so I increased the mist frequency and durations so I could (and by could I mean MUST) run the fan more, so that everything was dripping wet and soggy all the time. So you can see the counter-intuitiveness of my situation. I don't want to mist 6 times a day, but apparently I have to, given that I'm blowing 35% to 40% RH air in on a regular basis. Erring on the side of caution, as to not make frog jerky, the conditions are probably too wet in there, and I say this although my background is mostly dry, & my planters on my background require manual watering, believe it or not, and FYI, my mid-viv/foreground plants barely have time to dry off in between mistings. I'm paranoid to run the fan if the plants are dry, as I'm sure you can understand.
> 
> ...


This is a perfect example of how complex the situation can get. This is also why I don't use fans directly on the outside or inside of the vent. It is just too efficient. That's why I use the fan setup that I do. Blowing straight at the vent on either side of it just has so much potential to dry things out. Blowing obliquely ALONG the vent seems to work better. In your situation, I might have tried putting a couple of more layers of screen directly under the vent to prevent some of the air exchange. This assumes that you don't have a way to dial the fan back either in terms of its power or some sort of timer like Doug was suggesting.

As for the computer fans in the humid enclosure even directly in the path of the Mist King nozzles, I have been pleasantly surprised  I have no idea why, but the computer fans I have used in all of my enclosures have been much more tolerant of mist than I would have thought possible. I can't really explain why, but I don't think I have had to replace a single fan due to rust/corrosion in any of the 8 tanks I have them in. I don't go out of my way to point the nozzles at the fans, but it still ends up that way sometimes and the fans just seem to sit there and take it. I use computer fans with a controller (made for a bay in a computer tower) with knobs on it to control 4 fans at a time. As long as you get the right AC adapter that can handle the load of the 4 (or fewer) fans you plan on using, it has worked great for me so far for several years.

I hope you get to the point where you aren't chasing your tail anymore on the ventilation/misting cycle.

Best of luck,

Mark


----------



## serial hobbiest (Mar 5, 2017)

Encyclia said:


> This is a perfect example of how complex the situation can get. This is also why I don't use fans directly on the outside or inside of the vent. It is just too efficient. That's why I use the fan setup that I do. Blowing straight at the vent on either side of it just has so much potential to dry things out. Blowing obliquely ALONG the vent seems to work better. In your situation, I might have tried putting a couple of more layers of screen directly under the vent to prevent some of the air exchange. This assumes that you don't have a way to dial the fan back either in terms of its power or some sort of timer like Doug was suggesting.
> 
> As for the computer fans in the humid enclosure even directly in the path of the Mist King nozzles, I have been pleasantly surprised  I have no idea why, but the computer fans I have used in all of my enclosures have been much more tolerant of mist than I would have thought possible. I can't really explain why, but I don't think I have had to replace a single fan due to rust/corrosion in any of the 8 tanks I have them in. I don't go out of my way to point the nozzles at the fans, but it still ends up that way sometimes and the fans just seem to sit there and take it. I use computer fans with a controller (made for a bay in a computer tower) with knobs on it to control 4 fans at a time. As long as you get the right AC adapter that can handle the load of the 4 (or fewer) fans you plan on using, it has worked great for me so far for several years.
> 
> ...


I'm considering ordering two (one for a back-up) USB powered 40mm brushless mini fans (~ 8 cu.ft/min). That should be plenty for my 18x18x24 enclosure, shouldn't it?


----------



## Encyclia (Aug 23, 2013)

serial hobbiest said:


> I'm considering ordering two (one for a back-up) USB powered 40mm brushless mini fans (~ 8 cu.ft/min). That should be plenty for my 18x18x24 enclosure, shouldn't it?


Yeah, I don't see a problem there. You may only need one for a tank that size. Since I assume there isn't a way to dial down the fan, you may have to control the humidity a bit more with positioning the fan than you would if you were able to turn it down. I am betting you can find a position that does what you want it to do, though.

Mark


----------



## serial hobbiest (Mar 5, 2017)

Encyclia said:


> Yeah, I don't see a problem there. You may only need one for a tank that size. Since I assume there isn't a way to dial down the fan, you may have to control the humidity a bit more with positioning the fan than you would if you were able to turn it down. I am betting you can find a position that does what you want it to do, though.
> 
> Mark


I was gonna plug it into my basic timer anyhow (multiples of 30 minute intervals), or do you figure a small fan like that ought to be running continuously?


----------



## Encyclia (Aug 23, 2013)

serial hobbiest said:


> I was gonna plug it into my basic timer anyhow (multiples of 30 minute intervals), or do you figure a small fan like that ought to be running continuously?


The timer will add some more tools to play with to get it dialed in, but you will only know how to dial in the fans exactly when you try it. It is just a matter of trial and error.

Good luck!

Mark


----------



## jarteta97 (Jun 13, 2014)

Does anyone have suggestions for a basic timer that can be programmed to have the fan run for a certain number of minutes repeated every one to two hours? Something that isn't super expensive?


----------



## Austindg13 (Aug 31, 2017)

jarteta97 said:


> Does anyone have suggestions for a basic timer that can be programmed to have the fan run for a certain number of minutes repeated every one to two hours? Something that isn't super expensive?




Found this one.

Century 7 Day Heavy Duty Digital Programmable Timer - Dual Outlet (Single Control) https://www.amazon.com/dp/B00MVF16JG/ref=cm_sw_r_cp_api_cMpEAbM1YPGMW


Sent from my iPhone using Tapatalk


----------



## Andrew Lee (Jan 21, 2014)

I recently visited another frogger's home to pick up a few frogs and noticed that in his tanks, he had computer fans blowing lightly across the vents, at an almost 30 degree angle. Kind of sounds weird but imagine an xy axis. The x axis represents the vent and the fan was at a y = 2x angle. But then the fan was around 10 inches away and blew a very light breeze. Condensation was minimal but still present I believe. I think that prevented the tanks from drying out too fast while still encouraging air movement. So kind of like what the others said, don't point the fan directly into or out of the vent. Just my random input


----------



## DanConnor (Apr 12, 2009)

For my current build (350 g) I'm using 4" inline duct fans externally plumbed in to bulkheads in the glass canopy. Should create plenty of air movement without introducing dry outside air.


----------



## Encyclia (Aug 23, 2013)

DanConnor said:


> For my current build (350 g) I'm using 4" inline duct fans externally plumbed in to bulkheads in the glass canopy. Should create plenty of air movement without introducing dry outside air.


That's a whopper of a tank, Dan!


----------



## jarteta97 (Jun 13, 2014)

Encyclia said:


> That's a whopper of a tank, Dan!


I agree, would love to see its build progression.


----------



## viper69 (Dec 28, 2013)

braydens said:


> Ive kept tree frogs for a number of years (red eyes, tiger leg, whites) and have found they do a lot better with air circulation. I should mention this is with a 2" vent. i have air blowing in through the vent and within (depending on tank size)




Have had tree frogs myself, not tigger-legged yet. What species have you owned, and what beneficial differences did you notice when using a fan with the tigers?


----------

