I have a air cleaner in my tent, things began herming, i tracked it down to the blue indicator light, i have since put a piece of tape ovr the light, prob solved.
Distance...put the back of ur hand at the top of the canopy, count to 60, if the back of ur hand is hot it is to close....it will b alright to use hps all the way thru ur grow
It works... I do it aftr evry harvest...just put it in 20 hour light and watch it reveg in approx 60-90 days...if it dont reveg, i lost nothing, if it does reveg now u have a plant that has estab roots and it will finish approx 2 weeks than it did the first time.