apparently anything over 18 hrs is more than the plant processes,so anything more is waste of electricity.and for your second question...there's really no such thing as too much light.

dive
divestoned Reviewed by divestoned on . quick question actually 2 quick questions. can i leave my light on my plants 24/7 till flower? and my next question is should i bother getting a 75 watt hps to add to my grow box? Rating: 5