You don't have a chance with a 400w HPS in a rubbermaid grow without a cooltube. With a cool tube it can be done however you are going to need a nice fan to cool it off. It depends what ducting you have to use and how many bends you are going to have in the duct to determine how big a fan you need?
jtsik330 Reviewed by jtsik330 on . Heat/Cooling Issues Hi there. I am halfway through building a Rubbermaid Box. I was planning on using CFLs, however I have been given a 400w HPS bulb socket ant ballast. So Just how powerful of a fan should I be looking at purchasing, seeing as this bulb nearly melts the plastic without one? Or should I be looking at cool tubes? Cheers for the Help Rating: 5