I'm waiting on a CoolTube with a 400w HPS light. I know that I will need a fan for this (it's going to be lighting a 2' x 2' x 6' space in a cabinet).

My present plan is to mount the Cooltube at about 5' high. Given that my babies are in a 15" high Waterfarm, that means they'd never be more than 3' or so from tons of light -- far more than they'd be getting from just about any configuration of CFLs, no matter how close I could get them.

My questions are:

• where should I place the fan?
• how big a fan will I need?

Can you attach an inline duct fan directly to the open end of the CoolTube (i.e. the one without the socket) or do you need to put some ducting between them? If the former, installation should be relatively easy. If the latter, I may need to do a bit of thinking.