# Cooling my vivarium with a mini fridge



## grabberorangestang (Jul 26, 2013)

Hello Everyone!

So I have been having problems with temperature in my viv since the summer started to creep up. During the day I was peaking at 83 inbetween mistings. Last year I can remember a thread I posted in where we debated between using a fridge to cool the water in the viv or a TEC cooler to cool the air.

I took a fridge (IGLOO 1.7 CuFt) and a aqua lifter pump, I ran lines from the tanks water basin, through 80 ft of tube in the fridge, and back into the viv. I have to go to Lowes today to get insulated tube, but here is my jerry rigged setup. 

Once I am done tinkering with it I am going to move the fridge into the stand. I am also thinking about putting another 50ft of tubing in the fridge and tacking the lines in the fridge running parallel lines up and down the walls of the fridge to get the most surface area. I think coiled up there is less contact with the cold air.


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## Dendro Dave (Aug 2, 2005)

grabberorangestang said:


> Hello Everyone!
> 
> So I have been having problems with temperature in my viv since the summer started to creep up. During the day I was peaking at 83 inbetween mistings. Last year I can remember a thread I posted in where we debated between using a fridge to cool the water in the viv or a TEC cooler to cool the air.
> 
> ...


This is pretty much the exact system I've been planning to build into a viv, so I can keep Pseudotriton ruber. My theory was that the extremely low flow of the tom's pump would allow for better cooling (by keeping it in there longer then typical water pumps) before the water exited the fridge

If you have trouble pumping through that much tubing you can plumb multiple tom's pumps into the 1 intake line, and 1 output line, but if you wanna go with a bit better vacuum pump, look at the Avast Marine in this thread...
http://www.dendroboard.com/forum/parts-construction/168890-dendro-daves-vivarium-tech-finds.html

I look forward to seeing how this works mr Guinea pig 

P.S. My thinking on how I'd try it was to put some gel or ice pak to freeze in the freezer part, then get some container that fit in the fridge and fill that with water to submerge my line while it cools. Thought that might help max out the cooling potential.


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## toostrange (Sep 19, 2013)

Why couldn't you put it below and custom build a res. like a sump. Use low flow pump. Mabye like 5 gal or so, seems it may be easier to cool that way. Prolly could even put filters on it.


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## nish07 (Mar 16, 2008)

Filling a bucket inside the fridge and using a temp probe in the viv water to say when to turn off or on the pump would be better as the water would start cold and would gain less heat from a small amount of viv water when it was cycling. I think that's what the previous poster was saying. You might have to tune it because the water would end up being fairly cold when it swapped in but you can change the temp where the pump shuts off to account for that.

I'm actually trying to find the cheapest way to cool a viv about 8 degrees different from the rest of the room so I'm looking into different things atm. Using a mini fridge was something I considered years ago I just never tried.

-Nish


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## grabberorangestang (Jul 26, 2013)

Thanks for the additional input everyone. And thanks dave for that marine pump, I think I might be buying one!

I thought of another idea going off of yalls sump idea. Since my tank isn't drilled, what if in line with the pump I put a 2 gallon sealed container that the pump would suck from? Do you guys know where I could find such a thing? Make one myself?


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## Dendro Dave (Aug 2, 2005)

grabberorangestang said:


> Thanks for the additional input everyone. And thanks dave for that marine pump, I think I might be buying one!
> 
> I thought of another idea going off of yalls sump idea. Since my tank isn't drilled, what if in line with the pump I put a 2 gallon sealed container that the pump would suck from? Do you guys know where I could find such a thing? Make one myself?


I'm not sure I follow, wouldn't the coiled tubing and/or the reservoir in the fridge basically be a sump? 

...I was thinking that for non-drilled tanks you could just use a 2nd pump to pump the water from the viv back into the cooling reservoir. I was also thinking mistking seconds timers would be ideal for fine tuning control.

like you could have one timer pump water into the fridge for say 30 seconds, and the other timer pumping water out of the fridge back into the reservoir at the same time for 30 seconds... and just keep doing that. You'd probably have to fiddle with the times, and I don't remember how many events the mistking timer has, but you'd probably wanna use the max number of events to keep regularly replacing the warmer water in the viv with the colder water from the fridge. 

One possible obstacle is no 2 toms' or avast pumps are probably going to pump at exactly the same rate due to distance/height/length of tubing/particulates in the water/pump wear etc..etc.. I don't know if the pressure created as both pumps pump in/out of the reservoir would equal things our or possibly cause the lines to blow/reservoir to burst due to pressure 

*But maybe that is all pointless*  ...Shouldn't this work just by pumping the water out of the viv, and having the longest/coiled length of tubing be the input/suction side of the system, and it gets cooled as it gets sucked out of the viv, through the fridge, and into the pump outside the fridge, then the output hose runs right back into the viv (insulating both tubes sections outside the fridge might be good idea)... or vise versa? Basically as long as the pump can suck the water through all that tubing in the fridge that should work shouldn't it (assuming enough tubing/water stays in there long enough to cool adequately before getting pumped back into the viv (That's why I think low flow is ideal for this))


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## nish07 (Mar 16, 2008)

I'd personally drill the tank and pump water in and let it overflow out of a bulkhead. I would put the drain on the other side of the viv from the tube pumping cold water in. 

Cooling the water at the bottom of the tank should cool the whole tank. You can put a temperature on/off probe in the water closer to drain bulkhead area and fine tune when it needs to be pumped based on viv temperature.

The tub of water in the fridge would stay cold if it was a large enough tub. You can drill the sides of the minifridge (watch out for wires, pipes and the plate that has the coolant in it they are in different places in different fridges) and just seal the tube in and out with expanding foam.

You can have a filter on the tube coming from the overflow from the false bottom going into the tub and keep it cleanish.

-Nish


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## grabberorangestang (Jul 26, 2013)

Correct the suction side has all of the coiled tubing as of now and then pumped directly into the tank. What I am saying is on the suction line drill a 2.5 gallon bucket with a in and out nipple. (Bucket is sealed) The pump would then suck all the air out of the bucket filling it with water to where the outlet nipple is and then pumped back into the tank?


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## grabberorangestang (Jul 26, 2013)

Thanks nish. Looking back on it, I agree your idea is the better of the two. But With the viv being established and not drilled already I would prefer not to drill the tank.


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## Dendro Dave (Aug 2, 2005)

grabberorangestang said:


> Correct the suction side has all of the coiled tubing as of now and then pumped directly into the tank. What I am saying is on the suction line drill a 2.5 gallon bucket with a in and out nipple. (Bucket is sealed) The pump would then suck all the air out of the bucket filling it with water to where the outlet nipple is and then pumped back into the tank?


Ya that looks right to me, only wouldn't you get a little better cooling efficiency, if your input (warmer water from viv) was pumped into the top of the reservoir inside the fridge, and the output (coldest water in fridge) came from the bottom (since heat rises/cold sinks)???

Oh but nish has a point at least in that if you take water from the other side of the tank that might be best. Because you want to pump the warmest water into the fridge, not a mix of some of the coldest and warm water back into the fridge. 

So cold output from the fridge on one end of pond (or false bottom), then take the input(warmer water) from the other side, basically creating a thermal gradient across the water area in the viv. You could further increase cooling efficiency I think if you suck out water from the warmest top layer of the water column at the farthest point away from the cold water input, and have the cold water input inject water into the lower part of the water column.

So basically, blow water in low, suck it out high from both the fridge and the viv to take advantage of physics(or in the case of the fridge would you want it coming in low and going out low?). 

Circulating/filter pumps may mix up the warm/cold water in the viv pond, but I bet you'll still get enough differentiation overall that it will benefit the system to do it that way. 

Then there is no reason why we can't also have a fan on an interval timer blowing down on the water surface in the viv further cooling the water and internal viv temps. If you wanna take it a step further, plumb in a cool mist system on an interval timer also.

So a 3 part cooling system...

1. The heavy lifting is done by the fridge system.
2. Fans add evaporative cooling.
3. Cool mister adds cool mist to further cool the system, and possibly help replenish lost humidity due to fan use. 
(you could set your timers so the fridge pumps cool water in regularly all day/night, but fans kick in periodically during the day, then the cool mist mid day, or just run it all a much as possible if you don't have to worry about it getting to cold at night 

Another idea I'm toying with since I have 2 small window unit AC's in my living room about 15 feet apart is to capture some of the cold air coming out through like a funnel and tube that runs into the viv with block of foam what wicks moisture up from the pond (I can hide all this with hardscape/plants), so basically it is cold AC air, blowing through wet foam creating a swamp cooler effect. Again you can add fans, cool mist humidifier, or even the fridge system, so could make it a 4 part system 

In my instance with these Window unit AC's blowing out 50-60 degree air, I may just be able divert some of the air right into the viv and with the viv sitting between the 2 AC's it will already be in the coldest area of the room. I thought it might be to much airflow though, so that is where the wet foam at the end came in to tone down/disperse the hurricane, while simultaneously adding to the chill. 

slapping some foam insulation panels on the back, sides and bottom of viv, basically just leaving the front view area and lid area as normal should help the system get cooler and stay cool longer if something fails, and temps more stable over all conditions.


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## nish07 (Mar 16, 2008)

I think just cooling the false bottom water would be like an anti-heat mat and be the best way. I think that just the flow regardless of where you pumped water in and out (as long as one is on the opposite side of the other) is enough to mix the water to a good temp. 

It would be better if the water being pumped into the viv was not low in the viv or it might siphon drain the false bottom so something slightly higher than the drain would be best. Allowing the water to flow out of the fridge and into the false bottom with an air gap would possibly let the water in the tube 'only' slide down back into the bucket (without siphoning false bottom water) and keep from sitting in the tube and getting warm.

Water in a fridge should be around 40-45 degrees I'd guess and that would honestly be enough to keep a viv down 5-10 degrees in temperature.

The only other option is a chiller and the cheapest ones are 450 dollars for a decent one. The only benefit to those is they only run when they need to chill the water while a refrigerator keeps the contents cold all the time so I don't know the difference in electrical costs. I tend to think a used minifridge would be cheaper for quite a while.

-Nish


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## Dendro Dave (Aug 2, 2005)

nish07 said:


> I think just cooling the false bottom water would be like an anti-heat mat and be the best way. I think that just the flow regardless of where you pumped water in and out (as long as one is on the opposite side of the other) is enough to mix the water to a good temp.
> 
> It would be better if the water being pumped into the viv was not low in the viv or it might siphon drain the false bottom so something slightly higher than the drain would be best. Allowing the water to flow out of the fridge and into the false bottom with an air gap would possibly let the water in the tube 'only' slide down back into the bucket (without siphoning false bottom water) and keep from sitting in the tube and getting warm.
> 
> ...


I think with diaphragm/lifting pumps given they way they work, you don't have to worry about siphoning back... but I'm not certain, never happened with my tom's pump at least.

I build all my ponds so they share the false bottom water, so I would basically be doing what you suggest. 

There are the thermoelectric coolers for wine and stuff, but seems like while some have gotten them to work it is harder to get things as cold as you want and keep them that way. I think the mini freezer in the old school fridges gives them an edge over thermoelectric, but as this is all still theory for me, I could be wrong 

P.S. Since you're going to have water pumping into the viv, you could just make it a waterfall... a cold waterfall


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## nish07 (Mar 16, 2008)

It'd be a really cold waterfall and probably not be great for some frogs D=

But an underground waterfall that dropped water at the top of the false bottom would be good IMO. I think a large enough tub of water (4-5 gallons) would stay mostly cold or cool whatever water that was pumped in between the water changes.

-Nish


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## Dendro Dave (Aug 2, 2005)

nish07 said:


> It'd be a really cold waterfall and probably not be great for some frogs D=
> 
> But an underground waterfall that dropped water at the top of the false bottom would be good IMO. I think a large enough tub of water (4-5 gallons) would stay mostly cold or cool whatever water that was pumped in between the water changes.
> 
> -Nish


Oh I'm wanting to do this for these...


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## grabberorangestang (Jul 26, 2013)

Well I must report back and say I sealed the lines with insulated tubing. And the temp is 79 degrees. I will let it run for a few days and then I will plumb in the container for more cold water. If neither ideas work I guess the viv is going in the basement.


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## planty (Jul 12, 2013)

For my little shrimp tank I used a second hand water bar









Take the front panel off, seal the cooling "bath" with glass and silicone, and attach the in and out tubes straight to a pump. It works exactly like the coolers you get for aquariums, only smaller  and cheaper 

As for flow, you should go fast rather than slow, the temp in the cooling chamber and in the water in the viv should be the same. If you think about it makes sense. Just like you should put your heater in front of your flow.


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## Ed (Sep 19, 2004)

Much simpler is to just make the tank well ventilated and let evaporative cooling work it's magic.. 

Keep in mind that each and every one of the pumps that people are using use the water to dump heat from their operation. 

Some comments 

Ed


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## Dendro Dave (Aug 2, 2005)

grabberorangestang said:


> Well I must report back and say I sealed the lines with insulated tubing. And the temp is 79 degrees. I will let it run for a few days and then I will plumb in the container for more cold water. If neither ideas work I guess the viv is going in the basement.


Aww that is disappointing. What is the flow (gph) of the pump? ...Did you allow the water reservoir in the line and/or fridge to completely cool before you started pumping? Maybe if it starts cold it will stay coldish 



planty said:


> For my little shrimp tank I used a second hand water bar
> 
> 
> 
> ...


Neat Idea, pics/more detailed "how to" would be cool. I'm looking around for prices. it is a *Tana* brand water bar it seems. 

Not sure I agree about the high flow though. If the water in the viv is being warmed fast enough while being circulated through the chilled area rapidly, and back into the warm area again and again... it will never get a chance to cool down mush. It seems like with a low flow pump and the water moving slowly through the system it would have longer to be more thoroughly chilled, and even at just a few GPH you'll replace 10+ gallons every 3 hours with a toms pump I think (3.5gph)... or 5gph with this sweet lil pump...
Avast Marine Diaphragm pump is the mother of all top off pumps

Yes less water would be dumped into the system in a given time frame, but the water that was dumped into the viv may be much much much colder... and be able to keep you in the desired range before the room can warm the water back up to much. My guess is there some optimum flow rate vs cooling capacity, and hitting that sweet spot of balance would yield the best results. So maybe in some ways we're both right LOL, just depends on your individual system and environmental circumstances???

Anyways, maybe there is some aspect of thermo/fluid dynamics I'm missing, but I think of it like if I rapidly stuck my hand in and out of a freezer vs slowly putting it in, then slowly pulling it out... pretty sure it would get colder faster that 2nd way  (But admittedly I could be totally wrong) 



Ed said:


> Much simpler is to just make the tank well ventilated and let evaporative cooling work it's magic..
> 
> Keep in mind that each and every one of the pumps that people are using use the water to dump heat from their operation.
> 
> ...


I agree if you need just a few degrees, and you can use both at the same time can you not?

...I'll have to fire up one of the tom's pumps I have, but I don't think they got very warm, or at least didn't seem to warm the water much. Also if the lil waterfall/aquarium pumps we use, or tom's style pumps heated the water significantly wouldn't we see a lot more temp related frog deaths, or at least noticeable temp climb during their operation? 

I don't doubt that some heat is added, but I bet in most cases a chiller and/or evaporative cooling would more then make up for what the pump adds. Again for dart frogs might be enough, but in my particular desired application I don't think fans are going to cut it when my home is usually around 72-75 degrees year around and I need to be at 60F or below for P. rubers, or an average max of 65F from what I've read.


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## Spaff (Jan 8, 2011)

Dendro Dave said:


> I need to be at 60F or below for P. rubers, or an average max of 65F from what I've read.


Max of 65F for what? Day temp? There are populations of P. ruber as far south as Louisiana and eastward to Florida. I'm sure their habitat is a bit cooler due to their association with streams, but high air temperatures in those areas are well above 65F for 9+ months of the year


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## ecichlid (Dec 26, 2012)

Dendro Dave said:


> Oh I'm wanting to do this for these...


 That would make a nice bass lure.


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## planty (Jul 12, 2013)

Dendro Dave said:


> Neat Idea, pics/more detailed "how to" would be cool. I'm looking around for prices. it is a *Tana* brand water bar it seems.
> 
> I just took the pic off of Google, it could be any brand... once you get it and see how it works its pretty straight forward. you've got two lines, just waiting for you to hook up to you're filter
> 
> ...


If you go this way you'll have to get a temp controller, cause those coolers are intended to cool down to 4 degrees Celsius, and you don't really want that


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## dendrothusiast (Sep 16, 2010)

I'm going to bounce off Ed's evaporative cooling method since it seems to be working for me. I have a large high elevation tank for specific orchids that has a false bottom for water to collect in. What I did was install the sherman vents that have a 3/4 inch gap for air flow. Now since I'm also growing bromeliads in there that demand a consistent flow of air throughout the day I also added a 92mm fan to provide it and out of pure luck I was seeing good drops in temps where they went down to the high 60's. 

It was a miracle for me since I rarely turn on my ac and live in los angeles where we get some hot days out here. I have to mist more for this tank but I'm fine with it since I still manage to grow some moisture loving things in there.


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## Dendro Dave (Aug 2, 2005)

Spaff said:


> Max of 65F for what? Day temp? There are populations of P. ruber as far south as Louisiana and eastward to Florida. I'm sure their habitat is a bit cooler due to their association with streams, but high air temperatures in those areas are well above 65F for 9+ months of the year


Well the research/care sheets seem to indicate 50-65F, max of 70F maybe, and one report of one being found under a sign or something at 80F... but ya some of the subspecies range pretty far south.

Ideally I find some nice red ones from Florida or Georgia on kingsnake or somewhere for sale, but I'm not sure they'll always have the collection site data. I think I emailed about some a year or 2 back and the seller couldn't tell me where they were collected and I don't know enough to identify the subspecies by sight. Some recent CB success might make some available, and if so I'd have a pretty good idea of what worked for them with those particular animals.



ecichlid said:


> That would make a nice bass lure.


Ya, or better yet trout... but I don't think I could do that to one of these 



planty said:


> If you go this way you'll have to get a temp controller, cause those coolers are intended to cool down to 4 degrees Celsius, and you don't really want that


Well if what you have looks just like the pic you posted it should be a Tana brand. Oh for others who might wanna try it, this might be helpful...
http://www.tanawatercyprus.com/index.php/how-the-t6-works

I've looked at the chillers for aquariums. My thoughts were based on the DIY setups that people were building is that they just weren't efficient enough to do that much cooling with that high a flow rate, where as the the purpose built aquarium chillers were powerful/efficient enough that they could do the cooling at high GPH flow rates... And it seemed like a less powerful cooling method would benefit from having the water in the cooling area for longer before it got dumped into the habitat, but again could be wrong. 

You might be right about the temp controller too, but you'd probably wanna factor in how large the reservoir is on the water bar vs how much water volume is in your habitat. If that thing only chills a pint or so of water down to 4'C and you're dumping that cold pint into 30 gallons of water, that isn't so bad... now if you're dumping it into a gallons worth of water that might over chill your critter 



dendrothusiast said:


> I'm going to bounce off Ed's evaporative cooling method since it seems to be working for me. I have a large high elevation tank for specific orchids that has a false bottom for water to collect in. What I did was install the sherman vents that have a 3/4 inch gap for air flow. Now since I'm also growing bromeliads in there that demand a consistent flow of air throughout the day I also added a 92mm fan to provide it and out of pure luck I was seeing good drops in temps where they went down to the high 60's.
> 
> It was a miracle for me since I rarely turn on my ac and live in los angeles where we get some hot days out here. I have to mist more for this tank but I'm fine with it since I still manage to grow some moisture loving things in there.


Nice, what were your room temps? I think diverting air from my window unit ac will work for my P. ruber project (if ever it actually happens), the one catch is winter... I might have to run the AC in winter, while the heat is also on which will cost more money, but econ mode might be enough and not to expensive, or maybe just keep the house under 70F and let fan/evaporative cooling do the rest. This viv will very likely rest on the floor, or a short stand to benefit from colder air there. I left a thermometer under one of my window unit AC's and it stayed around 60F for days, so that is promising. Could just set the viv under there, with a strip of venting and let the cool air from the AC and evaporative cooling do the chilling work, probably.

-------------------------------------------

P.S. Found this chiller pretty reasonably priced...
http://www.amazon.com/ActiveAqua-Chiller-refrigeration-unit-10/dp/B0048IVBT4/ref=sr_1_1?s=home-garden&ie=UTF8&qid=1401476432&sr=1-1&keywords=water+chiller

and this one...

http://www.megagrowers.com/elemental-h2o-chiller-1-10-hp/

and this one...

https://www.google.com/shopping/pro...TfoATA7oD4Bw&ved=0CIwBEPMCMAI&prds=scoring:tp


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## dendrothusiast (Sep 16, 2010)

Dendro Dave;1970881
Nice said:


> Hey Dave my average temps are between 75 - 80. Since summer is around the corner I'm curious to see what my temps are going to be like but on the hottest days we've had so far this year (105) temps were no higher than 75 during the day and then 70 at night. As long as the temps stay cool majority of the year I think I'm in the clear but I'll still be watching.
> 
> I'm not sure how well this method will work on smaller tanks so I tried using little ceramic pots under the substrate and it seemed to help a little but I could not afford the extra weight so I am rigging a mini soda cooler in the same fashion most nepenthes growers rig theirs but on a smaller scale for a smaller growing space.


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## Ed (Sep 19, 2004)

Spaff said:


> Max of 65F for what? Day temp? There are populations of P. ruber as far south as Louisiana and eastward to Florida. I'm sure their habitat is a bit cooler due to their association with streams, but high air temperatures in those areas are well above 65F for 9+ months of the year


And very rarely are the salamanders up above ground during those temperatures.. We get those temperatures up here as well and at those times of year, Pseudotriton is generally closely associated with cool/cold water seeps and sloughs... 

Some comments 

Ed


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