Looking to update my light situation, right now I'm using a 4 blub T-5 set up. It works nice but looking for something more during the flowering period. I have seen 400 W systems on E-Bay for 135.00 and was wondering what the feelings were out there with these systems. Also my next question is does a air cooled light reqiure a fan and tube connected to it to keep it cool? Thanks for the help in these matters.
I assume you are talking about a HID kit, in which case yes it converts watts consumed to lumens better than T5s -- though the T5s close that gap down significantly compared to CFLs and standard fluoro tubes. And yes, an air-cooled hood is designed to have ducting and a fan attached to actively draw the heat away.