I keep my tanks at ambient temperature. I was using heaters in some of my tanks but ended up removing them all. They are good during ich and other parasite treatments. I used them to raise the fish's metabolism in growout tanks but the benifit was not noticable.
Btw, I had a system of tanks running at 95F for around six months without any problems (my Chinese Hillstream Loaches hated it but survived). I keep air stones in all of those tanks.