Right now my 75 gallon is at 80 degrees on me deep blue thermometer is that bad? I try to lower it a notch on my jager heater. Hasn't really budged from 80.
Mine bounces daily from 81-82. The other day I forgot to plug my cooling fans in for lights and my was at 84 when I got home. Corals didn't seem to mind the warm bath at all and doing just fine.