using a fish tank complete with live tropical fish for cool

The alternative to direct air cooling

Moderators: NeilBlanchard, Ralf Hutter, sthayashi, Lawrence Lee

Post Reply
sburns88
Posts: 20
Joined: Mon Sep 25, 2006 1:44 pm

using a fish tank complete with live tropical fish for cool

Post by sburns88 » Mon Aug 13, 2007 3:15 pm

I am planning on using a fish tank with live fish for use as a radiator and reservoir. I am currios as to what problems that could be encountered and can it be done safely with regards to the fish.

I am looking to cool the following set up

radeon x600 graphics (not sure though)
athlon X2 1.92 ghz processor

not other components are going to be cooled

the reason why i thought of this is that my fish tanks heater broke down and i am looking to kill to birds with one stone.

I am planning on using a fish tank filter not a pump so solid waste shouldn't be to much of a problem.

ddrueding1
Posts: 419
Joined: Sun Sep 19, 2004 1:05 pm
Location: Palo Alto, CA

Post by ddrueding1 » Mon Aug 13, 2007 3:24 pm

The biggest problem will be temperature control. You are putting in a certain amount of heat that you cannot change. You will need some system for either adding or removing heat from the system if it gets outside the range desired by the fish. What temp do the fish prefer?

ddrueding1
Posts: 419
Joined: Sun Sep 19, 2004 1:05 pm
Location: Palo Alto, CA

Post by ddrueding1 » Mon Aug 13, 2007 3:31 pm

According to here:
The ideal temperature for most freshwater tropical fish is be between 76 and 80 degrees F.
That temperature seems possible to maintain. Depending on how large the tank is (therefore how much heat it loses over time).

You will need an active way to remove additional heat; either a small radiator with a fan that only turns on when the water exceeds the optimum range, or something more unusual (fountain to increase heat loss?). The easy part is to include a heater that only kicks on when the temperature goes too low (or your computer turns off).

Of course, other people will chime in with more practical concerns, like the fact that you won't be able to add anti-corrosive stuff, and the water will almost certainly be dirty enough to clog your water blocks.

Wedge
Posts: 1360
Joined: Tue Mar 25, 2003 10:59 pm
Location: NorthEast Arkansas, USA

Post by Wedge » Mon Aug 13, 2007 3:52 pm

It's a bit creative, but I think it's a bad idea.

Have you cleared this with the fish?

scdr
Posts: 336
Joined: Thu Oct 21, 2004 4:49 pm
Location: Upper left hand corner, USA

Post by scdr » Mon Aug 13, 2007 7:25 pm

Use care in selecting materials for the portion of the cooling system that contact the aquarium water with regards to toxicity. Materials like copper can be bad news for fish.
My father talks about doing research in a marine biology lab at the university. They used tap water for some of the fish tanks, but ran into problems because the city would occasionally run some copper compound or something through the water system (to clean the pipes, I believe). It wasn't a high enough dose to bother people, but it would kill some of the animals they were working on.
Of course the crucial question there is the dose - and I don't know the details of what animals and plants are sensitive to what concentrations of what metals/plasticizers/etc. And how much of that will come off of a heat exchanger over time - but it would be worth finding out what materials would be safe.

As noted in previous post, using the aquarium water directly for cooling would be a really bad news. (Impossible to keep your cooling system clean.)
It might work to use a 2 liquid system - the coolant liquid liquid running from water blocks through a heat exchanger to heat the water in the tank.
How to keep the aquarium side of the heat exchanger clean would still be a concern. (Buildups of algae, etc. would tend to decrease cooling efficiency.) But could presumably build some heat exchanger that would have larger passages and be easier to clean than having to regularly dis-assemble, flush, replace, whatever your water blocks and hoses in your computer.
You could check the wattage of typical aquarium heaters to make sure you would be cranking out heat in the right ballpark to keep your aquarium warm. And the temperature of input water in a typical water cooling rig to be sure that 80degree input water is cool enough to cool your components.

Unless your computing load is quite constant, regulating the temperature (as the heat input from the computer goes up and down with load) might be a challenge.
Last edited by scdr on Mon Aug 13, 2007 7:33 pm, edited 1 time in total.

ronrem
Posts: 1066
Joined: Sun Jan 16, 2005 2:59 am
Location: Santa Cruz

Post by ronrem » Mon Aug 13, 2007 7:27 pm

ddrueding1 wrote:The biggest problem will be temperature control. You are putting in a certain amount of heat that you cannot change. You will need some system for either adding or removing heat from the system if it gets outside the range desired by the fish. What temp do the fish prefer?
70-80 is a good range for most fish....plus or minus 5 F would be no big worry. Is the water being directly used through the puter and in the tank? If so....Copper may be a problem.

Best would be a heat exchanger in a plastic bag or such so the fish water is not interacting with copper + aluminum. Likely-the limited interaction of a copper CPU heatblock would not be too bad-but it being hot MIGHT accelerate some copper getting into the water.

IF you are doing this in a LARGE tank....50+ gal,letting it supplement a regular thermostatic heater is great stuff-and you can set it up easy so the Computer water and fish water do not mix-but the temps equalize.
Even a long section of submerged plastic hose would give some heat transfer at no risk to fish. Of course you also don't risk sucking a small fish up and frying him on your CPU.

ddrueding1
Posts: 419
Joined: Sun Sep 19, 2004 1:05 pm
Location: Palo Alto, CA

Post by ddrueding1 » Mon Aug 13, 2007 9:30 pm

Keeping the water separate is a good idea, but if you are aiming for 80F in the tank, you want as much heat transfer as possible. If you don't completely equalize the temperature of the water, than the water running through your water blocks will be higher than 80F; too high IMHO. Submerging a radiator would be the easiest way to submerge a radiator. Is anodized aluminum OK for fishes?

m^2
Posts: 146
Joined: Mon Jan 29, 2007 2:12 am
Location: Poland
Contact:

Post by m^2 » Tue Aug 14, 2007 3:46 am

Maybe a custom, double-wall aquarium?

sburns88
Posts: 20
Joined: Mon Sep 25, 2006 1:44 pm

Post by sburns88 » Tue Aug 14, 2007 3:52 am

I am probally going to do the radiator method as this would be the most safe method as i forgot (rather stupidly) that copper leakage from the blocks will be toxic to aquatic life.

What radiator would be suitable for this.

Caenis hilaris
Posts: 7
Joined: Mon Apr 10, 2006 6:24 am
Location: Baton Rouge, LA

Post by Caenis hilaris » Fri Aug 17, 2007 9:38 am

I'm practicing fisheries biologist on the faculty at a large southern US university, and my 2 cents are that you are going to face 3 major problems. First, tropical fish have tight thermal tolerances. I've lost dozens of fish due to heater failures. You risk both exceeding and not reaching thermal tolerances during operation. Second, if you use the water directly, you will need to filter the water coming into and out of your water cooling. Fish aquaria tend to be rich in ammonia, which tends to breakdown making the water slightly acidic. So, you'll need to not only remove algae, plankton, etc., but also bring the water back to cirumneutral before encountering the water blocks. If you use a radiator in the tank, how will you keep it clean? Also, how can you be sure that it won't react with the water? How will you move water through the radiator without impinging fish? Lastly, leaks will be catastrophic.

I've given some thought to this myself, and I came up with these problems. The best thing for a quality aquarium set-up is a appropriately matched heater on a UPS (no dead fish since these were set up), and the best thing for a computer is its own water cooling set-up. I use a set up built of Swiftech parts and even in the sweltering Louisiana summer, my computer runs cool and quiet.

sburns88
Posts: 20
Joined: Mon Sep 25, 2006 1:44 pm

Post by sburns88 » Sat Aug 18, 2007 2:52 am

I have decide to set up the computers water cooling independatly of the fish tank. thanks for the advice though

Post Reply