Well speaking of chillers after reading 2MH=HOT. Is the ground temerature pretty much all the same through out the world. Except for cold palces i know (permafrost). How affective do you think it would be to run a large amount of piping under the ground out side of your house with pump on it. DO you think this would act as a cheap way to chill. Kind of like a septic field in a way. You can have it on in the summer and have the pump the pump on thermostate of some sort and then you can use earths lower temps to chill your aquarium. Crazy i know mainly theorietical but hey i figured id through it out to you guys.