Pump/powerhead Question

[madmom]

I posted a couple of day ago but may have worded it wrong. What would be a good sized pump for a 10 gal u.s. tank? I don't want to suck the fish up or have the output so strong as to push the fish all over the tank. I am trying to build a chiller . I am not using an old fridge since I've heard they don't work that well and knowing me I'm liable to blow up the house. (I'm an electrical disaster waiting to happen ).

 

[andywg]

If you aren't using a fridge, how are you plannign to do it? The only other way I can think of is to sink pipework into a bed of cement and further into the ground.

 

[madmom]

andywq;
Well basically I was going to run a tube from the aquarium through the pump into a chest of ice or icepacks and back into the tanks. The tube will be coiled to cool the water off inside and should slowly lower the tank temp. (hopefully) without shocking the fish

 

[Bignose]

Why let the cold water get into the tank at all? Why not use a closed loop of cold water that goes through the fish tank and then back to the ice-filled one. This tube will be cold and will cool the fish tank water the tube comes into contact with, and then you won't have to worry about sucking up a fish or shocking them with the temp difference.

 

[andywg]

That's actually a very good idea by Bignose because it would allow you to have as large a pump as you want circulating the colder water and should not provide a splash zone of ice cold water, the water in the tank would only cool as quickly as the thermal conductivity of the pipe would allow.

I must admit, though, I am struggling to see how a bowl of ice would be better than a fridge (or even a freezer?). Most domestic fridges have generally been abvle to cool by around 2 degrees C from my reading on other websites (some more, some less - I'm sure you appreciate the huge nujmber of variables involved).

With your plan you will have to be frequently doing maintenance on the ice packs, or ice, to make sure the required amount is stil there. The fridge would be one to setup and away you go. But I will be interested to see how it gets on.

 

[madmom]

andywq
It does sound do-able but wouldn't the water freeze eventually n a closed circuit like that ? I was going to use a styrofoam ice chest like those you take on picnics. Ice in those melts very slowly when the top is on it so it shoould last a good part of the day. If it works I'll post it.

 

[andywg]

If you use a fridge it shouldn't freeze. On a freezer it might, you could probbly work out the cooling effect you would need and find the cooling effect of a freezer.

You could run a freezer on a timer, though I suspect that a fridge would work better if you set it up right (the important thing is to make sure the holes into and out of the fridge are sufficientyl air tight and, if possible, insulated to prevent excessive heat loss.