hot spots are usually caused by the foil reflecting radiant heat energy, not the light focusing kind of burning (like a mag. glass on a bug trick) tin foil reflects heat as well as light, if he uses cfls for a grow, the only risk from tin foil would be a fire from a short, and maybe the box getting to hot.
4x5 Reviewed by 4x5 on . My First Grow :) hi everybody :D My plants are only 1 week old. can you critic my plant and my light system. ...my light system.. 3*30W CFL = 600W have a nice time Rating: 5