I deal with heat in all my tanks all the time because I have no
air-conditioning. I open the top, I put on the ceiling fan and open all
the doors and windows. I drop in freezer bags that I usually use for
sports injuries and replace them when they thaw. You can buy the
reusable filled bags at the drug store. For the s/w tank I keep a
bottle of distilled water in the refrigerator and top off as frequently
as I can. I raise the s/w tank's light (65 pc) up on a couple big
cleaning magnets, but at 84 degrees water temp I turn the lights off on
all tanks including those that house critters (turtles, toads, frogs) as
well as fish. Even the ocean has cloudy days, so I don't think I'm
stressing anyone by a bit of darkness.

On another subject: I've read that a spot of aquarium friendly epoxy
will take care of aiptasia if there are only a few. The ssmall squirt
of boiling (distilled) water seems to have worked for me.

Ruth Kazez