I have change. Not my whole tank is at 80 degree. With LED light instead of MH, my tank does not get that high anymore.
Rod Beuhler, of Rod's Food, have the oldest Gigantea in captivity that I know(20+ years) said in the past that he keep his anemone tank in the mid 80's and notice that it look off if the temp fall below 80. Knowing this, and did not want to rung my chiller too much I set my temp high. I did not find any problem with keeping temp this high consistently. However, I keep it at 80 degree and does not notice any problem either.