What is a cool tube, and how does it cut down UV rays?
sinky Reviewed by sinky 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