[pogodzib]

Maybe. 83-84 degrees is the highest I ever want to be. I've seen plenty of soft corals get stressed out and SPS corals get RTN and die at 84. Anemones may start to loose their zooplankton at 84 degrees and start turning white or transparent. If you want to get rid of ich, I'd suggest that you quarantine your fish for 6 weeks BEYOND when you last see signs of ich on your fish and leave your DT fallow at 82-83 degrees during that time.