There are some discussion on the temperature here. However, I am still confused. I understand that I should keep tropical fishes at 78F. However, temperature was rising in the last week and I don't have AC in the room in which I have aquarium. Temperature is gone past 85F and I cut off all heater/thermostat but still temperature is around 85+. Do you have any suggestion to control the temperature down (other than putting AC in that room or moving aquarium to AC room)?