I'm using the coralife aqualight Pro w/250w MH on a 65 gallon aquarium. The light has two fans both on the top. It is enclosed in a custom hood that has two 4" fans blowing cool air across the tanks surface from the back and two 4" sucking warm air out the top. I've had some heat issues due to the MH in the tank, but no issues with the light inside the hood.