Thanks for the info! Hey, Tony, did you realize you suggested all 3 ways

I like the one in and one out as well. I know my Coralife has 2 fans pulling air in and 2 vent holes for the air to come out. If I build either one, it will be open on the bottom for a pendant style and on the back for a canopy, that is what makes it a bit harder to decide.... I'll also set up the fans to be on a seperate timer to shut-off 20 minuts or so after the bulb goes out..
Walter