Ground green wire to any surrounding black wire - always-on computer PSU - plug in as many fans as your rails will handle.

I was going to do that for my PC grow box, but I decided against it and just went with a 12VDC wall wart.
khyberkitsune Reviewed by khyberkitsune on . PC Fan Power Supply I found a site with power cords for PC Fans: Dayton Blowers: REPLACEMENT 6' POWER CORD FOR AXIAL FAN - Fans, Blowers & Ducting - Environmental Control - Discount Specialty Farm, Greenhouse & Garden Supply Store - Horticulture Source . Box Layout: Flower Chamber - 3' x 3' x 6', Mother Chamber - 1.5' x 3' x 4', Clones Chamber - 1.5' x 3' x 2'. The only reason I had not planned to do PC fans was the power cord for them as I read that while it is easy to wire something like an old car Rating: 5