I am not post this to bash LED but all the MMJ and other types of growing lights have dangers so be wary and careful. Good sunglasses and hats like a baseball cap or bigger brim are minimums. Also if you are going to spend a lot of time in the room, turn off the bright lights or dim them. I personally hate metal halide because it can and does cause skin cancer. CMH, though I never used, is pretty scary because the light almost arcs. Some be careful everyone. This video is very good. Again - I am not bashing but everyone be safe.