My 180 hovers around 80 to 82 in the summer as well. Again not by choice...no chiller yet. The hot days with a fan full blast, it stays around 82 to 83. On an average though I strive for 78-80.
Just a few weeks ago I was away from my house for a hot hot wknd, couldnt keep the fans going because I wouldnt be around for water top off's. I got home and it was at 90! And probably was there at that temp all wknd.
Lost half my corals and 3 fish., tank was all cloudy fish stresse
Time for a chiller.