# Cooling vivarium



## sp.moss (Jan 1, 2019)

I just want to ask, how do you guys keep your vivariums cool during hot days?. 
I’m building a plant only tank and no frogs.


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## Harpspiel (Jan 18, 2015)

sp.moss said:


> I just want to ask, how do you guys keep your vivariums cool during hot days?.
> I’m building a plant only tank and no frogs.


It’s much easier to heat than cool - I’ve tried evaporative cooling with fans and standing water, ice packs, a series of tubes running through a mini fridge, and a custom Peltier junction cooling device. The Peltier junction is inefficient but does work, fans blowing over water will give you a degree or two, but really the easiest way to cool is to use an AC unit to cool the room the tank is in, or to find the coolest spot in your house and place the tank there on hot days (for me, bedroom closet on the concrete slab).

What temperature is the vivarium getting to and which plants are unhappy? Often for “intermediate” cloud forest plants, night temp drop is more important than staying under a certain temperature during the day.


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## IShouldGetSomeSleep (Sep 23, 2021)

I keep mossy frogs, if there's a heat wave I put a bag of ice overtop the Viv


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## JasonE (Feb 7, 2011)

I run a small personal ran across the top of the tank on hot days. This usually takes my tanks out of the low 80's into the high 70's. This is completely useless if you're dealing with some kind of extraneous circumstance, like your AC going out during a heat wave. This just works on those 100+ days where my upstairs temps peak a little higher than usual.


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## sp.moss (Jan 1, 2019)

What temperature is the vivarium getting to and which plants are unhappy? Often for “intermediate” cloud forest plants, night temp drop is more important than staying under a certain temperature during the day.
[/QUOTE]

It’s a newly build viv about 2 days ago so nothing much change except mold growth, for temp i’m still finding a hygrometer or temp gun but safe to say it’s above 27.c, simple to say it’s really hot that turning on the ceiling and stand fan at max and i’m still uncomfortable to sit or lay down in the room.

This is my viv
Plants:-
Neoregelia fireball
Philodendron scandens 







Ignore the chiquita linda down there.


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## sp.moss (Jan 1, 2019)

Harpspiel said:


> It’s much easier to heat than cool - I’ve tried evaporative cooling with fans and standing water, ice packs, a series of tubes running through a mini fridge, and a custom Peltier junction cooling device. The Peltier junction is inefficient but does work, fans blowing over water will give you a degree or two, but really the easiest way to cool is to use an AC unit to cool the room the tank is in, or to find the coolest spot in your house and place the tank there on hot days (for me, bedroom closet on the concrete slab).
> 
> What temperature is the vivarium getting to and which plants are unhappy? Often for “intermediate” cloud forest plants, night temp drop is more important than staying under a certain temperature during the day.


I mess up the reply, read on the previous post


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## Harpspiel (Jan 18, 2015)

Those plants will probably be fine up to around 32, maybe even higher. I wouldn’t worry about it. My tank with Fireballs gets up to 32 in the summer.


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## Socratic Monologue (Apr 7, 2018)

Plant people: how (if at all) does ventilation help plants grown in a terrarium cope with high temperatures? Is there any tweak that can be made in that regard to improve things on hot days?


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## Harpspiel (Jan 18, 2015)

Socratic Monologue said:


> Plant people: how (if at all) does ventilation help plants grown in a terrarium cope with high temperatures? Is there any tweak that can be made in that regard to improve things on hot days?


That’s a tough one, and these suggestions are a combination of guesses/anecdotal. It’s not easy to identify mild heat damage in my plants, they seem to just “languish” over days or weeks and then perk up when it cools down. Last summer I think my _Selaginella picta_ got too dry while also too hot, and got brown leaf tips.

Anyway, aggressive ventilation could help counteract the lights raising temps a couple of degrees above ambient, but on the other hand I have read that orchids (and I assume other high elevation cloud forest plants) will tolerate high temperatures better with really high humidity (but roots on the dry side), and too much ventilation would definitely reduce humidity. So I guess a good compromise could be running a cool mist humidifier outside the tank intake vent, while blowing hot air constantly out the top of the tank with fans…I might try that this summer.

Most of my house is cooled with a swamp cooler which maxes out at about a 20F temperature differential, but when I get frogs I’ll be cooling one room with a window AC unit, which may actually allow me to grow a few of the cooler side of intermediate plants.


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## Apoplast (Mar 17, 2020)

sp.moss said:


> This is my viv
> Plants:-
> Neoregelia fireball
> Philodendron scandens


Those are quite durable plants. Even at 32C, with the little ventilation they should be fine. Just out of curiosity, what is causing the heat to be so high in the viv? I apologize if I missed this in your earlier posts. Is it the room temp? The lights? 



Socratic Monologue said:


> Plant people: how (if at all) does ventilation help plants grown in a terrarium cope with high temperatures? Is there any tweak that can be made in that regard to improve things on hot days?


Ventilation helps plants cool because they tend to cool like we do, via evaporative cooling. Plants open their stomata and allow water to be lost, cooling the leaf surface, when they are not water stressed. There are exceptions, CAM photosynthetic pathway plants, etc. But this is largely true. Because of this, plants are impacted by water in the atmosphere in similar ways to us. They respond to the vapor pressure deficit (VPD ) of water in the air. This is essentially a measure of how saturated the air is with water vapor at a given temperature (and pressure, but that tends to be less of a focus for various reasons). This is the same process that leads to heat indices in the summer in humid places. It is VPD that related to how well a plant can cool itself. Many animals, I believe, too (though I'd have to check with my animal physiologist friends on that, but the physics is the same, so...).

Specifically for a viv/terrarium, if you can ventilate it, especially with drier outside air, that will help immensely. Also, if you can reduce the heat load, which is why I asked above about source. There is a lot of condensation in there, and the lights look really close to the top, so moving lights even a few cm away might help.


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## Harpspiel (Jan 18, 2015)

Apoplast said:


> Those are quite durable plants. Even at 32C, with the little ventilation they should be fine. Just out of curiosity, what is causing the heat to be so high in the viv?


The OP stated their room was 27C and they weren’t sure of the temps in the viv. I said those plants would be fine at least up to 32C.



Apoplast said:


> Specifically for a viv/terrarium, if you can ventilate it, especially with drier outside air, that will help immensely.


I am not sure of the conditions in which plant stomata might open and exactly how they use evaporative cooling, but all of the literature I have read says that cloud forest plants will respond better to heat waves with adequate (probably 70+%) humidity and water. I wouldn’t try to evaporatively cool them using room air alone, unless it was about that humid. And yes, I know that the efficiency of evaporative cooling drops drastically with that much water already in the air. It’s possible that with cloud forest plants, the function of evaporative cooling when there isn’t adequate water would be more damaging than the heat. However, literature has also stated that keeping them excessively wet at the roots during heat waves can encourage root rot, so there’s definitely a balance.


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## Apoplast (Mar 17, 2020)

Harpspiel said:


> The OP stated their room was 27C and they weren’t sure of the temps in the viv.


My apologies for missing those details. That said, my purpose was to get the OP to think about where the heat was coming from.



Harpspiel said:


> all of the literature I have read says that cloud forest plants will respond better to heat waves with adequate (probably 70+%) humidity and water.


These are not "cloud forest" plants and the comparison is not useful. These are highly tolerant house plants. Acclimated, they will chug along at 15% RH in household temperatures. They'll be fine.


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## Harpspiel (Jan 18, 2015)

Apoplast said:


> These are not "cloud forest" plants and the comparison is not useful. These are highly tolerant house plants. Acclimated, they will chug along at 15% RH in household temperatures. They'll be fine.


@Socratic Monologue asked about cooling plants in general, not the two specific plants that the OP has. That question is what both you and I responded to, after we both stated that the OP’s plants don’t need to be cooled. So I suppose I should have added “assuming someone has plants that do need to be cooled”. Most of the plants that people are growing in vivariums alongside dart frogs, that would actually need to be cooled, are cloud forest plants - very often specifically pleurothallids.


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## Harpspiel (Jan 18, 2015)

Also, referring to things as “house plants”, while it describes their robustness and tolerance, I think does them a disservice by making them seem a little mundane. Neoregelia ‘Fireball’ may or may not be a cloud forest plant, and it has some pretty neat mysterious origins. Here’s the story. Either way it is certainly a tough and temperature-tolerant plant.

And here’s a neat article, in case the OP is interested, on why _Philodendron scandens_ is actually hederaceum (along with lots of other Philodendron species that used to be distinct).


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## Socratic Monologue (Apr 7, 2018)

Yep, I was just taking the opportunity to ask a general plant question that was suggested by the topic at hand. It isn't often that we talk about heat and plants, but given the OP's situation (in Malaysia, per earlier threads and the flag by the username) it seemed useful here.


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## motydesign (Feb 27, 2011)

you could program fans and turn your viv into a evap cooler. I can crash the temp 3 degrees if I run for 20 min fan durations. But right now since temps are great I’m just 10 min once an hour. If I up my CFM to be a bit noisier than I would like I could possibly get 4 maybe 5 but not willing to try next to find out.


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