You can leave the light on a auto 24/7 they bud regardless ive mostly grown photo periods and a few autos 18/6 works for them as well. they tend to be a bit shorter in my experience and start flower earlier oh and you still play the guessing game on male and female. As far as topping, and defoliating that doesn't pertain to auto or pp just how you want the structure of your girl . That is just my experience, different strains different gains.