i have a 28 gallon nano cube, i have my heater set at 75 so it should not be on, the hood has 2 fans built in when the lights are on but for some reason the temp has been hovering around 80 degrees F. what can cause this? also protein skimmers, when the air stone is old does it get hard to control bubble level? and what is the normal day night cycle? can to much increase algae growth? your help folks is always appreciated. thank you