Cooling A Tank

[Shovelnose]

This is what a 3 foot tank I used to keep Glyptothorax and other hill stream fish looks like. Lost most of the hill stream catfish when I was away in college for a coupla weeks. There was no power for 2 days straight in peak summer.

There are 2 600 lph HOB's and a 2000 lph pump in there for filtration,aeration and current. The 2 fans run 24/7 and manage to keep the water at around 26-27 C. The ambient temperature today is around 32 C with a humidity of 58 %. The temperature is likely hover around this mark for the next coupla months and drop a few degrees closer to October.

Keeping these figures as standard, can anyone suggest ways to cool the tank further so any new fish I get will be more comfortable. A small change I am doing (not related to bringing down the temperature) at the moment is clipping the outlet of two air pumps each to the HOB'S.

I do know bout the 'floating the bottle method' but wanted to check if there are any other effective methods.

How good or bad is dry ice??? My guess is its mostly bad as it is known to release CO2 but any pointers or suggestions in this direction will also be great.


PS : I am back to being a student now (allegedly) so don't have the budget for a chiller.

[racoll]

Unfortunately you might have to accept that you can't keep hillstream fishes at this point in your life. Perhaps look forward to when you are able to keep them, and look for some more tolerant species in the meantime.

[Bas Pels]

You wrote a chiller is not an option - too expensive. But is a fridge, containing an Eheim an option?

Used fridges will not cost that much - and you can easily drill 2 holes in the wall

If that does not work, you better keep other fishes as Racoll suggested.

Later, when you have your own home, you can drill holes in the ground to make a state of the art cooling system. But students don't tent to live near the ground, ususally

[Shovelnose]

Unfortunately you might have to accept that you can't keep hillstream fishes at this point in your life. Perhaps look forward to when you are able to keep them, and look for some more tolerant species in the meantime.

I dont think I need to take such a drastic decision. I am just looking for possible suggestions to reduce the temperature by a coupla degrees more maybe. Although 26 C is in no way ideal for these fish, they did quite well until the power cuts started.

You wrote a chiller is not an option - too expensive. But is a fridge, containing an Eheim an option?

I am afraid I don't get this. Can you elaborate this please???

[racoll]

I am afraid I don't get this. Can you elaborate this please???

Just buy a small, cheap second-hand refrigerator, drill some holes in it, and pump your aquarium water through it. A pump and a load of coiled pipe would do the job.

[Shovelnose]

Got it now. Thanks. Lets see what I can do.

A friend made a chiller out of an air conditioner. Its right here : http://indianaquariumhobbyist.com/commu ... 89&start=0

Most of it is way too technical for me. I will probably get electrocuted if I even try something like this.

I have been obsessed with using dry ice since yesterday. Can anyone suggest anything on this??? Good idea??? Moronic idea??? Sub moronic maybe???

[Bas Pels]

very bad idea

Dry ice is frozen CO2. Frozen gasses expand a lot when they thaw, replcing a lot of air. @ 0 C, only 44 g dry ice will push 22 liters of air.

CO2 is what we exhale, and if this stuff happens to be in your room far too much, it might kill you - but if it is in your room @ sub- sub lethal doses, it might damage your sleep, resulting in bad study results - something you should not want to even consider.

Besides, the stuff is hard to control. I don't know whether you intend to put it into your tank or use it to let the water flow along, but in each case cou cannot really know what will happen.

I will not go into the costs involved, I know what students might be able to get for free - having the right contacts at the university. But someone will have to pay for it

[sidguppy]

the fridge suggestion is spot on.

the hose in the fridge shouldn't be too thin; sometimes even an old fridge can cool quite a bit and a thin hose can freeze and burst.
the best would be 16-22mm soft pvc hose, the clear green ones that you use for eheims and such

rolling it up: make a pile of the hose, only 1 hose thickmess; to get it upright in a spiral a large bucket is ideal;
you can roll the gose around it and then ducktape it to the bucket. pile 2 buckets upon each other (with the bottoms in the center, bottom to bottom) if you want to make a huge cooler.

now if you pump the water through, the best way is to pump it UP in the fridge. so the lower end that comes in the fridge is attached to the outlet of the pump, the upper end goes back to the tank

circulation:
there are 2 ways; you can pump your tankwater through the hose; this is the easiest way.

safer, but involving more tinkering and DIY is to make a closed circuit. the hose will next to the fridge also be piled in the biofilter of the tank and tankwater is pumped through or over the hose-pile in the biofilter.

for obvious reasons you need a fairly strong pump, but it doesn't need to pump very fast

the longer the water stays in the hose in the fridge, the cooler it becomes

it's a lot of work setting it up, but it's also a lot more cheap than buying an aquarium cooler

another trick: if the fridge has a freezing compartiment, you can make ice and toss that in the bucket where the hose is wrapped around

NEVER put the hose in that co partiment, cause it'll sure cause an ice blockage and a burst hose

if you got the simpler set up that would cause your tank to empty in the fridge....

good luck on the tinkering ;)

[Shovelnose]

Thanks Bas. Exactly what I was looking for. Will avoid dry ice.



Hey Alex,

Thanks for the detailed reply. Will get something up and running in the next few weeks. And if I dont, you can say NI to me.

[Shane]

There are 2 600 lph HOB's and a 2000 lph pump in there for filtration,aeration and current. The 2 fans run 24/7 and manage to keep the water at around 26-27 C. The ambient temperature today is around 32 C with a humidity of 58 %. The temperature is likely hover around this mark for the next coupla months and drop a few degrees closer to October.

Firstly, your design above using computer fans is really smart!

I have used the frozen water bottle method, heck I have even just tossed handfuls of ice in aquariums, but it is a very short term solution to get through a heat wave. Just keep about four small drinking water bottles (500 ml) in the freezer and change them out every morning. Make sure you add them for the first time on a weekend so that you are around monitor the temp. I have never kept records when doing this, but it would be interesting if you did with the goal of coming up with some general guide lines.

Have you experimented with unplugging some of the power filters? The motors can significantly raise a tank's temp. I found when experimenting with Chaetostoma and Chiloglanis that there is a point of diminishing returns where the current/O2 added by powerheads (pumps) is negated by the amount of heat they themselves generate (since warmer water holds less O2). You might try unplugging the 2000 lph pump, adding an external air pump with some airstones, and seeing how much of a temperature drop that provides. The airstones will not replace the loss current, but O2 levels will stay about the same, and even increase, if the tank's temp is lowered.

-Shane

[Shovelnose]

Hey Shane,

I am at the moment trying to figure out how effective the fans are really and how much the power filter is increasing the tank temperature by. So I am trying to find out temperature when

a) The fans are switched

b) When the power filter is switched off.


Maybe one I find out the numbers, you can tell me if the 'bottle method' will help in this situation as I have been skeptical 'bout using this method for no particular reason.

[WhitePine]

I have also used the frozen bottle method on a small reef tank with great success. I could drop the temp of the tank by about 5 to 7 degrees. The fans are a great idea but would work much better if you had them blowing across the tank. Evaporative cooling works much better with lower humidity. Is there a way you can setup the pump outside the tank? I think the best Idea is still a fridge.... and in cooler months you can use it to chill tasty beverages!

[Shovelnose]

I initially wanted to keep the fans in such an angle that they cover the entire tank but they are quite heavy. Keeping 'em at an angle would be risky. One of the fans is right above the power filter to negate the increase in temperature (at least partially).

Humidity here is high most of the time except when everyone pretends it is winter during October-December. Its just rains and there is a little less sunshine.

[Shane]

To get the fans blowing across the water you would likely need to build a hood out of wood and mount the fans on one side.

Found this very well written article.
http://reefkeeping.com/issues/2003-06/nftt/index.php
and this useful video
http://www.youtube.com/watch?v=ATsu-WOs ... re=related

Both are focused on marine tanks, but the concepts are universal.

-Shane

[stumac]

love the fridge idea, defo the way forward!!

[WhitePine]

You could actually just raise one side of the fan support to put an angle on it.