Polarhound,

It doesn't need to be at 82F. Oscars can be happy in the mid 70's. The
ideal temp range for Oscars is 73-82.

Keeping Oscars at 64 will get you a lethargic unhappy fish. As well,
what happens if your heat goes out during the colder months? Even in
the south the temps can get down to frost-forming levels.

What happens if my heat goes out during the colder months? Probably the same
thing that would happen if I use a heater and the power goes out during the
colder months. :-)

The fish I have now can handle colder water no problem (many of them can
survive the winter in lakes here and I live in Salt Lake City, UT). I've
been toying with the idea of heating my smaller tank up into the 70s but I'm
just not sure I want to take that route.

Thanks.

Jonathan