[DrSalsa]

Hi Everyone,

I'm building a 3' tall column tank at the moment with internal air circulation powered by computer fans, as I understand the air circulation should help keep the viewing glass free of mist and water droplets.

I've built some ducts colleting the air at the bottom of the tank and expelling it toward the front and side panels (tank is viewable from two sides). See image below. The two fans are small 4cm ones, but quite powerful, I can feel the air current coming out the exhausts and even at the oposite side of the tank.

So I decided to try it out before building my bg. I filled by false bottom with water, turn on the heaters and left the air circulation on for 24h. .... well, I wasnt impressed, there was consdensation everywhere, even just in front of the exhaust.

So, what am I doing wrong?

1) bad positioning of the in- and exhausts?

2) Shouldnt be blowing hot humid air towards the glass?

3) should not have the air circulation on all time?

4) the fans are not powerful enough?


Any tips would be greatly appreciated. Just wanna get on with my background, but need to sort this one out first.

 

[parkanz2]

If the difference in temperature from inside the viv to outside the viv is great enough, I don't think any amount of air circulation will defog it unless you bring in outside air which will dehumidify your viv.

A lot of people do it for the well being of the plants I think. Many people also heat their entire frog room which really reduces condensation issues.

Maybe some others will have some better news for you... Do you have any ventilation to the outside of the viv planned or is completely enclosed?

 

[dfrmav]

Air circulation can be on all the time or only on with the lighting. Your call. How big are your fans? Full speed? Biggest issue I have with what you described is the heating. That is probably your problem because heat makes water evaporate more, and you have to realize that 1) your viv may not be as hot as you made it, and 2) your viv won't have a huge open body of water in it like you currently have in your test setup. Also did you have lights on? I find that that also helps keep condensation down, if lights are on.

 

[Pumilo]

Dfrmav has some good points about heaters and the huge open body. I'm confused about the ducting. It seems like that would be stealing a lot of CFMs from what is already a small fan. A good fan by itself will give plenty of circulation. If it is too weak, the ducting won't help, it will only steal flow. Sorry, but I'm not a "fan" of the ducting.
What is the CFM on your fans?

 

[DrSalsa]

Dear All,

Sorry it's taken me so long to reply (pressure at work mounted a lot and had to stop all distractions), but I'm now back on track with my tank.

Many thanks for your replies, all really good.

Parkanz2, the tank is a display tank in the dinning-room, so heating the whole room is not really an option. The viv will not have outside ventilation other than when I feed the frogs and do tank maintenance. I've seen others do tanks like this with good results...

dfrmav, cheers for your comments. All of my previous tanks were heated with water heaters in the false bottom and always managed to get really controlled air temperature that way (of course accompanied with condensation at the top of the glass). There will be about 25l of water in the false bottom, which is not huge, but should do the job regarding temperature regulation (there will be a trickle of water running along the back). And regarding lights, i'm using a LED hood, which produces near to nill heat, which I guess it has it's advantages and disadvantages.
How do you heat an individual tank if it's not through warm water and without using heat lamps (which I dont see as appropriate for amphibians)??

Pumilo, thanks for the ducting advice. The fans are
Sunon 40x20mm MagLev Fan (KDE1204PKVX) which have a 10.8 CFM. I think that the ducting was indeed compromising their efficiency, so I've got rid of it and will be mounting them independently, see if it helps.

Many thanks again for your answers and I hope to be a bit more constant with my replies (work permitting)

Tara,

Nik

 

[Pumilo]

What's your overall viv size? Just as a guideline/starting point, I have a 3 foot tall, 75 gallon viv with a single, 21.5 CFM fan in it. It seems to be just enough to keep it clear most of the time but mine has no pond.

 

[pgravis]

I have an 18" cube viv, heavily planted with a small water feature. Condensation was a constant problem, so I built a small fan (found the plans by searching on here). It just went up two days ago. I positioned it back in a nook in the background pointing straight at the front glass. When I wake up the tank is slightly fogged, but once the lights go on it is pretty much fog free. It is also the little 40 mm computer fan. Hope you can figure it out, as I am way more impressed than I expected. Even as I built it I considered not finishing it because I was skeptical!