I agree with Justin.
As long as you aren't running metal halides, your house AC
, should do it.
I live in south Florida, it's hot!! I keep my AC
at 75, and my tank runs at 78-79 degrees, under T5's.
Each tank will vary slightly because of the amount of other equipment, each pump adds a little heat, and size of tank, a larger tank is more stable than a smaller one, but IMO
, you should be OK without a chiller.