DIY Chiller or am I crazy?

[Rikko]

I think the main problem with cooling our tanks is just that chilling technology isn't very good. Even a full size kitchen fridge can't do as much as you'd think. It kicks into the duty cycle by cooling the air inside the fridge, but before long everything in there is cold. No cold air is really being lost because it's so heavily insulated. Like has been said before: temp drops a bit, compressor goes back into action, then off again.

But now run some warm aquarium water through it and ask it to constantly be cooling that water down.. How much, really, can a fridge be expected to cool when there's a neverending supply of water heated by the pumps, lights, even the surrounding room?

Lots of guys have good luck using bar fridges to keep their tanks cooler during the hot summer months, but I think for any serious temperature control (ie. try running a 90 gallon Pacific Northwest biotope system), we just can't do it.

I remember one guy in Cali dug a huge hole in his back yard and ran several dozen feet of tubing underground to the water table and then back up.. It was sufficiently cool down there to keep his tank well under control,