The last few days my 175 gallon has been up around 80-81 degrees. I did have it at 77-78. I know the temperature has been going up outside, but I didn't have this problem last year with my 110 gallon tank. Is it because of the mag 24 is much bigger than the mag 12 that I had on my old 110? I removed a section of glass on the canopy today to see if it helps but no luck. I also unplugged both heaters today and here it is almost 10:00 pm and its still 81 degrees. I hope I dont have to buy a chiller. lol Any suggestions on how to keep it cooled? I might have to buy a fan.