Reduce water used / pump suggestions?

[Henway]

I'm in California and we're having a bit of a drought problem. I feel guilty about using so much water from my Jamil whirlpool immersion cooler and may be required to reduce water anyway. I typically water the banana trees with the water, but that might be overkill.

Anyway, I have a 1000G pond with koi that I could use as a heat-sink. I could get a pump and pump the pond water through the immersion chiller. I did a quick calculation and added 48L mass of water at 373K to the pond of 4000L @ 293K, and there will be a 4.5C change--about 10 degree change in the pond. Probably NOT good for the fish. If my figures are wrong, PLEASE TELL ME!

Hmmm, I guess the jacuzzi will be a better bet....

Any suggestion for a pump for this? I believe it will only see water temps up to 80F and the water won't touch the beer, so it doesn't have to be food grade...

[straight cash homey]

I'm not a physical chemist but I remember a little, so don't take this as truth. I get an increase in temp of about 1 degree.
(48)(x-100)=-(4000)(x-20)
48x-4800=-4000x+80000
4048x=84800
x=20.9=final temp in C

I could be wrong.

Seems to make more sense though, I did another calculation to relate it to something smaller. This would be the same as having a pint of beer at 20C and adding one teaspoon of boiling water. that would also raise the temp by one degree C. a little easier to wrap your head around when related to something on our scale. again, I don't want to cook your fish, so double check.

[bcmaui]

I'm in California and we're having a bit of a drought problem. I feel guilty...

Don't feel guilty, you live in the desert, it's not your fault California is dry.

Irrigating the plants introduces water back into the water table under you and is not a bad thing.

If you still feel bad just don't shower on the day you brew.

[BigNastyBrew]

Irrigating the plants introduces water back into the water table under you and is not a bad thing.

+100 Good call. Lord knows we pump more than it replenishes as it is.

[bcmaui]

If you want to use some of your water twice, redirect your laundry machine waste water out to the bananas. They don't mind the laundry detergent and you water your plants every time you wash your clothes.

Just as when you brew, the same water is being used twice.