I've got 2 tanks (3g and a 5g) which are both heated by Hydor Theo 25w heaters. I live in NJ, and udring the winter months these heaters maintained each tank at a constant 78 degrees.
Now that the heat has set in (reaching 90 degrees outside) I'm having the opposite problem. I cant seem to keep the tanks any cooler than 82 degrees.
I dropped the Theo's to the 75 degree setting, and my air conditining is set at 76 degrees (central air).....both tanks are still reading 82 degrees. Both fish are active, eatting, and acting normal.
What have you all done to keep your tanks from getting too warm in the summer months? The tanks are located on the first floor and there is plenty of air circulation.