Of course it's a common rule not to place an aquarium near a source of heat just to entirely avoid all those possible issues that are bond to come from it, but has anyone every tried using a chiller to contract this. The only long section I have for a bigger tank in my house that is an exterior load bearing wall also happens to have a super big cast iron radiator almost the whole length of the wall. Lately I have been debating whether the use of a chiller would be able to keep water temp consistent for a larger tank during the winter when the radiator comes on.