[Myka]

Before you fork out the money for a chiller, have you looked at other options? Chillers may cool the tank, but they heat the room they are in A LOT. For me, a chiller would be a major last resort. How about turning your central air conditioning (if you have it) down a couple degrees? Buy a portable air conditioning unit (same price as a chiller) to cool the room down, plus you get to enjoy the cool. Fans on the tank and sump waters' surfaces (make sure the fans make ripples) blowing the hot air from the lights away?