yes, it's totally dark when light's out. WW has a longer flowering time, but they were 2 months old when I began the 12/12 stage. I just switched the bulb to HPS, but they seem to like it. It sucks bc we vegged for way too long, plants are too tall now, and it's taking forever to show buds. Just not all in all a very rewarding experience thus far. And my landlord almost found us out the other day-just walked right the fuck in with a new vent filter, headed strait towards the grow rooom. Had to intercept him in my PJs with no bra on, feet from the door, to tell him we already changed the filters. Damn! it just seems like more risk than it's worth.