stand in the room turn off oall lights in the room and make surte all the lights out side oare on and look for all the leaks mark them were they are and cover them i use trash bags but my room is still small and it works remember it takes less than a candle light to turn some plants back to vegg and then if they revert they can take few weeks like up to 6 weeks to get back to flower always test shit out befor you plant preperation is key to sucsex i mean success