they grow about 30"-36" tall, if given enough light, your 400 is fine ... outstanding plant, very tolerable, doesn't hermie easily, not a big feeder ... VERY potent, a sativa-dominant clear-headed high, can be very trippy, but usually not anxiety-producing ... be patient, wait until all trichomes are 'cloudy' before harvesting ... dry and cure well ... expect to flower minimum 8 weeks, possibly as much as 10 (disregard what the advertisers claim, watch your trichomes) ... if you take your time flowering and curing, you will have some smoke that will take a backseat to almost nothing ... :smokin: