I also desperately want to know by tomorrow what to get at home depot for the cooltube setup. I need to know the name of the ceramic socket that the bulb screws into, mainly. What would I ask the Home Depot geek for? And do they differ in size for HPS, MH and Mercury Vapor? Every time I go to this Home Depot, they're always suspicious. And it's not like I go in there blazed or wearing '420' patches or anything. i.e., I don't swerve in there lettin' my freak flag fly. So I don't want to ask anything like "How do I get a 400 watt HPS bulb into a cooltube with the stuff you have here?" - I want to ask for specific parts. Names of brackets, sizes, etc. I already have a 4" inline duct fan from there from a while back. And I know I need flexible 4" duct tubing, 4" metal sleeve for the cooltube... but what else? And do I need special drill bits to drill through the metal sleeve for the bracket placement?

And especially, what is the name of the bulb socket assembly?