I, too, grow autos under 24/7 and mine never droop unless they're either thirsty or have been overwatered... since they're drooping on you right after you water them, I'd say you're not letting them dry out enough between waterings. Make sure the pot is super light before giving them another drink! You don't have to abide by a strict schedule.. i.e., every two days or whatever... let the plants tell you when they need something. Autos can withstand drought better than they can withstand overwatering so if I'm ever in doubt, I will wait until they start drooping on me and then give them water or feed (whatever is up next for them) and they respond happily after about an hour or two.
And btw, do check out FreeCain's diaries (there aren't any) before you take advice!
Good luck with your grow... it looks fabulous!