I use a 400 watt light in a cooltube (plus some accent CFLs) in a 46"x20" area, with a 6" 440 CFM centrifugal fan for ventilation. Works grrreat. If you can handle the ventilation side of the equation, I'd get the 400 watt light - significantly better canopy penetration than a 250 watt light.
jamstigator Reviewed by jamstigator on . Is my light TOO powerful?? So i have a small, 2' x 2' grow space. But i have the opritunity to get a 400 W HPS cheap (for flowering). obviously it would have to be hung about a foot above the plants....it has a cool tube. Will it be more trouble then its worth? should i just go for a 250. Does anybody have experience using a big light in small area? Rating: 5