Lickert,
Thank you!
No, as long as the temp stays below 86, I've never had a problem. I think many folks keep their tanks in the 80-84 range. Any reef I've ever dove has had temps of 80 or more as well...
I have noticed coral stress when temps are prolonged at 86 or higher though and this tank has hit 88 a couple times. Nothing significant happened though, but the elevated temps only lasted a day or so. A couple things paled a bit, but recovered no problem. Still, under 84 is what I shoot for with daily fluctuation of 4 degrees or less.