temperature

[mark]

yep but nice thing about central air is the whole family can enjoy the cool, not just the fish

[BlueAbyss]

The only reason I could see you needing a chiller is if your temperature rises quickly or a lot over time, with your lights on. If the tank temperature bounces around, that's bad... stability is paramount in a reef tank.

[belzebuth]

If your tank get hot due to the lights been on, reverse your photoperiod. My lights go on at 9 PM. Works for me