^Thanks again! Looks like I'll explore more options. I though 1.5 complete air changes per minute would be plenty to provide fresh air and keep temps cool.

Huh, so you have a 6-inch fan exhausting through a 4-inch port? So you have a reducer and such?

I didn't realize the rectangular areas at the bottom were ports. Can you typically leave those open without light intruding? How do they pull that off? If that's the case then I'm set. I'll just get a couple 4-inchers and leave one of the bottom intakes open.

Well, I'm finally going to make it to the hydro store Saturday so that should answer a lot of my remaining questions. One thing though... where/how do you attach the fans? I'm not experienced with HVAC stuff, so I'm just curious how you mount them. Edge of reflector? Edge of grow tent? Middle of duct?

Peace, LP