Hi guys, I've just built myself a 3foot x 4foot x 7foot box(height). I've built a base for the box to sit on and insulated it since its directly on concrete. I've purchased a 600watt HPS light with a cooltube. I have a squirrel cage fan that I will be using to filter out the air through a home made carbon filter. Also going to hook up a series of 2 CPU fans to suck out the air from my cooltube. My question is this... I'm looking to make this as smell-proof as possible. How would I make my air intake smell proof? What type of fan should be used? Should it be on all the time? I'll be posting pictures soon of the box. I'd love to hear your opinions on how to properly vent this.. Also where would someone buy Mylar? home hardware store? Plant store? Thanks in advance!!!