Cooling Aquarium Water for NANF Species

[Fish Folk]

Whether you need to moderate tank temperatures during summertime heat spikes, or set cooler water conditions for particular fish species, sometimes aquarists need the _opposite_ of a heater. As ACO has neatly written up here, there are multiple options for achieving desired water cooling temperature goals.

I am experimenting with (1) wrapping my tank with some black insulation, and (2) running a fan. If you have found success with particular products, please do share! I looked around awhile,  and decided to go with these:

For insulation wrapping, I plan to wrap a 55 gal NANF tank between the lower edge of the upper rim and the upper edge of the lower rim - flat against the glass. I hope to just cover the back and sides. I'll use three sheets, and use Gorilla Tape to cover the edges and keep it from peeling away. This will require some effort, as my 55 gal tank is pretty immovable. The old-school blue background has worn down, and needs to be replaced.

I am told that a good fan can help lower water temperature by 3-5 degree Fahrenheit. This brand does not have many reviews, but looking through reviews of other brands, I thought I'd give this a try.

Right now, I have kept these wild caught (F0) Catawba River Drainage Greenhead Shiners (Notropis chlorocephalus) since March, 2023. They sometimes turn a bit red...

But this is what I am going for -- their full spawning colors...

Will keep this thread updated as this project moves forward. I have to believe that it's possible to bred these!

[Guppysnail]

The one unique method I found many years ago was robbing an old cat fountain of the pump with suction cups. I then stuck it at the top and created a sort of fountain to take the best advantage of any evaporate cooling I could. 

[AquaHobbyist123]

I have a fan from Amazon on my Catawba River (almost finished) tank. it works extremely well, cooling down the water significantly (feels like an actual coldwater creek). Unless you have an exceptionally hot room, I think that it would do its job for most purposes without insulation material. it has 2 settings, medium and high power. The one significant issue with this particular fan is that the bracket does not fit larger rimmed tanks (rigged it to where it's fine in my case). High power can be a bit noisy though.

https://www.amazon.com/gp/product/B0B2R438TJ/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&th=1

[Biotope Biologist]

Let me know how it goes! For marine water we use a chiller. In some areas it may be required to get the water down to 45-55 degrees Fahrenheit. Which I believe river run fish are used to the temperatures dropping that much from snowmelt this time of year
 

 

[Fish Folk]

On 12/27/2023 at 10:24 AM, Biotope Biologist said:

Let me know how it goes! For marine water we use a chiller. In some areas it may be required to get the water down to 45-55 degrees Fahrenheit. Which I believe river run fish are used to the temperatures dropping that much from snowmelt this time of year
 

 

Yeah, it’s very hard to go below 60°-F in a heated home without a chiller. I’m not ready for the $$ plunge yet… but my hope is to maintain ca. 62-65°-F, and simulate “spring” with improvised photoperiod change. Adding improved O2 nearer the substrate may also help. I plan to adapt my DIY venturi pressurized spray-bar down 6-9 inches to experiment that way. 

[Fish Folk]

Acquired cooling fan today. I’m underwhelmed…

 

[dasaltemelosguy]

@Fish Folk I may not be fully understanding what you need or what is acceptable but is an immersion cooler acceptable?  I put a couple of pictures of a crude employment of such but there's a lot of options that can be had for under $100. 

It seems that it could work best with canister filters, or any filters coupled to the tank via hosing. In its crudest incarnation, a longer filter output hose used and looped into a bucket of ice can cool with amazing efficiency:

  

 

 

 

 

 

 

 

For example, a typical 5-gallon bucket filled with ice with about 33% of the output hose length submerged, will reduce the temperature about 2*F/hour.

It will last for about 25 hours before replacing the ice. But the longevity and efficacy are based on the GPH and affected by the environment. 

The ice bucket line is yellow, the cooler option line is green. Please excuse the typo, it should read "25 hours" for the green line.

The above mentioned "cooler option" is a more permanent situation that can be had by replacing the ice bucket with a common camping cooler for about $50:

The efficacy is relative and not based on the absolute volume. That is, the performance is determined by the GPH, and the percentage of the output hose submerged in the ice water. Without computing the requirements for better accuracy, if about 33% of the output hose of most canister filters was submerged in this device filled with water, the tank temperature would match the temperature in the cooler in about 5 hours. The temperature could be 'regulated' by simply immersing a lesser % of the hose. 

 

 

 

 

 

 

 

 

 

 

Alternatively, there's a Peltier device. Strapping a cheap Peltier cooler to the output hose could reduce the temperature more predictably:

 

 

 

 

 

 

 

 

These run off of common, large, 12VDC 'wall warts'. It works but it's very inefficient and the fans are noisy. They are cheap though, like $20 or so. 

A more permanent solution could be done with a small, submersible pump in a camping cooler and an immersion cooler coil under the gravel. These tend to look like this as they are for home brewers and are known as Wort Coolers, but they also come in flat & compact shapes:

                              

The coiled cooler comes in a variety of flat designs and in stainless steel.  Or it's easy to unwind them and reform them into a shape you can use. All of these devices are under $60 and enjoy superb efficacy except for the strap-on Peltier device.

I may be way off base with your requirements and the amount of DIY desired, but I thought I'd mention this in case it proves of any value for you. 

Edited December 30, 2023 by dasaltemelosguy

[Galabar]

You might just bite the bullet and go for something like this: https://aquacave.com/jbj-arctica-1-15-hp-titanium-aquarium-chiller-dba-050.html

 

[Fish Folk]

On 12/29/2023 at 8:22 PM, dasaltemelosguy said:

@Fish Folk I may not be fully understanding what you need or what is acceptable but is an immersion cooler acceptable?  I put a couple of pictures of a crude employment of such but there's a lot of options that can be had for under $100. 

It seems that it could work best with canister filters, or any filters coupled to the tank via hosing. In its crudest incarnation, a longer filter output hose used and looped into a bucket of ice can cool with amazing efficiency:

  

 

 

 

 

 

 

 

For example, a typical 5-gallon bucket filled with ice with about 33% of the output hose length submerged, will reduce the temperature about 2*F/hour.

It will last for about 25 hours before replacing the ice. But the longevity and efficacy are based on the GPH and affected by the environment. 

The ice bucket line is yellow, the cooler option line is green. Please excuse the typo, it should read "25 hours" for the green line.

The above mentioned "cooler option" is a more permanent situation that can be had by replacing the ice bucket with a common camping cooler for about $50:

The efficacy is relative and not based on the absolute volume. That is, the performance is determined by the GPH, and the percentage of the output hose submerged in the ice water. Without computing the requirements for better accuracy, if about 33% of the output hose of most canister filters was submerged in this device filled with water, the tank temperature would match the temperature in the cooler in about 5 hours. The temperature could be 'regulated' by simply immersing a lesser % of the hose. 

 

 

 

 

 

 

 

 

 

 

Alternatively, there's a Peltier device. Strapping a cheap Peltier cooler to the output hose could reduce the temperature more predictably:

 

 

 

 

 

 

 

 

These run off of common, large, 12VDC 'wall warts'. It works but it's very inefficient and the fans are noisy. They are cheap though, like $20 or so. 

A more permanent solution could be done with a small, submersible pump in a camping cooler and an immersion cooler coil under the gravel. These tend to look like this as they are for home brewers and are known as Wort Coolers, but they also come in flat & compact shapes:

                              

The coiled cooler comes in a variety of flat designs and in stainless steel.  Or it's easy to unwind them and reform them into a shape you can use. All of these devices are under $60 and enjoy superb efficacy except for the strap-on Peltier device.

I may be way off base with your requirements and the amount of DIY desired, but I thought I'd mention this in case it proves of any value for you. 

Wonderful ideas! I have exciting homework. 

On 12/29/2023 at 9:46 PM, Galabar said:

You might just bite the bullet and go for something like this: https://aquacave.com/jbj-arctica-1-15-hp-titanium-aquarium-chiller-dba-050.html

 

Someday I may. The bullet $$ is high for now. 

[AquaHobbyist123]

What I think makes the one that I have work so well is that it has the 4 fans working in unison. Not done an official measurement of temp changes, but I know that my water was 70-72 degrees but is definitely well in the lower to mid 60s. The single fan output just might not be enough for that size tank.

Just my $0.02.

[Galabar]

On 12/29/2023 at 9:48 PM, AquaHobbyist123 said:

What I think makes the one that I have work so well is that it has the 4 fans working in unison. Not done an official measurement of temp changes, but I know that my water was 70-72 degrees but is definitely well in the lower to mid 60s. The single fan output just might not be enough for that size tank.

Just my $0.02.

How much evaporation were you dealing with?

Edited December 30, 2023 by Galabar

[AquaHobbyist123]

On 12/30/2023 at 12:51 AM, Galabar said:

How much evaporation were you dealing with?

Not much evaporation per se, but the fan does blow water and coupled with the fact that my flow system tends to splash, it has to be topped of fairly frequently. I'm going to create a hood soon to prevent this.

[Galabar]

On 12/29/2023 at 10:08 PM, AquaHobbyist123 said:

Not much evaporation per se, but the fan does blow water and coupled with the fact that my flow system tends to splash, it has to be topped of fairly frequently. I'm going to create a hood soon to prevent this.

Cool.  I ask because the actual evaporation is what cools the tank.  I'm not sure if condensing the water with a hood would just add the heat back to the tank... (?)  

Edited December 30, 2023 by Galabar

[Biotope Biologist]

My water is pretty consistently sitting at 65-67 degrees in the winter I do water changes with unheated water, and the water comes out of the tap at 55 degrees. This is enough cold water in a 20% water change to get my temps down to 60-62 for a couple days but it snaps back to 65-67 pretty quick. I am still unsure if cold water triggers my fish seeing as the minnows breed constantly year round and the trout im not even sure of their sex let alone their breeding behavior.

I think @dasaltemelosguy suggestions might prove to be useful.

[Fish Folk]

Thanks to all for the ideas! If I went just a bit more high tech (e.g. Canister filter) these ideas all become possible. But then… in a perfect world, all NANF tanks would run on a dedicated chiller. Until I do a serious overhaul (or make bank on selling some fish), I probably will continue to tinker with the cheapo approach. I was able to see temperature dip to 58°-F. I made a video update…

 

[Odd Duck]

Back in the days of early reef tanks before chillers became more common place, we used to use small apartment / dorm size mini refrigerators and run a stainless steel cooling coil through the wall of it and circulate tank water through the coil.  You adjusted the refrigerator temp with the dial and if you needed more or less cooling than you could get with the dial, you added or removed coils in the fridge so the water spent more or less time inside the fridge as needed.  You don’t even need to cut the coil, just reshape it and pull some outside the fridge.  But more cooling (unlikely to need on a NANF tank where you’re already fairly close) you would need a longer or spliced cooling loop.

Where you would like to cool multiple tanks, this might not be such a bad idea.  Amazon has one for just under $90.00 and I see they also have a stainless steel cooling coil for under $40.00.  You could add more coils for more tanks.  I don’t know of any chillers that could run multiple tanks unless they were on a shared water / filtration system.  You would need a pump for each tank to run multiple coils and it might be a bit of a Tetris moment to get multiple coils into the fridge, but I’m sure it could be hooked into a canister filter system for each tank.  You might even be able to acquire any cheap, used but functioning refrigerator if you have room by the tanks, and use it for a second fridge in the basement (ala mancave beer / soda fridge if you’re so inclined).  As long as you weren’t particular exactly how cold your sodas are.  😆 

[Fish Folk]

On 1/4/2024 at 1:25 PM, Odd Duck said:

Back in the days of early reef tanks before chillers became more common place, we used to use small apartment / dorm size mini refrigerators and run a stainless steel cooling coil through the wall of it and circulate tank water through the coil.  You adjusted the refrigerator temp with the dial and if you needed more or less cooling than you could get with the dial, you added or removed coils in the fridge so the water spent more or less time inside the fridge as needed.  You don’t even need to cut the coil, just reshape it and pull some outside the fridge.  But more cooling (unlikely to need on a NANF tank where you’re already fairly close) you would need a longer or spliced cooling loop.

Where you would like to cool multiple tanks, this might not be such a bad idea.  Amazon has one for just under $90.00 and I see they also have a stainless steel cooling coil for under $40.00.  You could add more coils for more tanks.  I don’t know of any chillers that could run multiple tanks unless they were on a shared water / filtration system.  You would need a pump for each tank to run multiple coils and it might be a bit of a Tetris moment to get multiple coils into the fridge, but I’m sure it could be hooked into a canister filter system for each tank.  You might even be able to acquire any cheap, used but functioning refrigerator if you have room by the tanks, and use it for a second fridge in the basement (ala mancave beer / soda fridge if you’re so inclined).  As long as you weren’t particular exactly how cold your sodas are.  😆 

I have been thinking about this now for more than a year. I am so glad to learn that other aquarists actually did it! 

[Odd Duck]

On 1/4/2024 at 12:38 PM, Fish Folk said:

I have been thinking about this now for more than a year. I am so glad to learn that other aquarists actually did it! 

Absolutely!  I’m sure you could do a search and find diagrams and plans.  Info on how long your coil needs to be for a set fridge temp, desired water temp drop below current water temp, etc.  It was all out there back in the day, after the internet became more widely used.  We didn’t use one on our first reef tank in ‘83 but a friend did on his and it worked well.  We did finally try one on a more complex tank set up we did in about ‘97 or ‘98 after we moved to Texas and by then there was more how-to stuff available on the web and chillers were still massively expensive.  It worked well and was much quieter than the fans because we also had it plumbed through the living room wall into a closet.  The fans didn’t cool enough in the closet - they were set up on an elevated refugium and on a sump.

[Beardedbillygoat1975]

58 is a great result with some cheap insulation, a lot of aeration and a small fan, great job @Fish Folk. 
 

@Odd Duckas I was going through the thread started to reflect on my experience with beer fridges, brewing setups and the like and so when I came to your report I wasn’t surprised that some home brewer reefer came to this as a diy! Definitely something to consider as I keep getting my son pushing me to setup an axolotl tank! 

[quikv6]

I use small USB desk fans on my axolotl tank. It has a mesh lid, so I just let the small fans sit on top and angle at the waters surface. In the summer, I use up to 3 small fans at one time. At other times, only one is needed. I keep the water temp between 60-64 degrees F.

Another reasonable good way to regulate the fan is with an Inkbird. There is an Inkbird model that does heating and cooling. You just need a small old style switch fan that will turn on automatically when plugged in if the switch is on a speed. (The USB fans require plug-in AND the press of a power button.) Simply plug the fan into the cooling plug, leave the switch on, and set the Inkbird to activate that plug at a desired time, and turn it off at a desired temp.