Auto vs. Photo, light hours.

No way to tell until flowering begins, if it starts at 3-5 weeks of age, and without going to 12/12, they are autos. 18/6 is the most effective light/dark ratio for autos and photoperiod plants in vegetative growth. No, going from 16/8 to 18/6 WILL NOT cause any hermaphroditism. Bag seeds always worry me though, most bag seeds are the result of hermies, meaning the seeds will have the genetics for being hermies too. Hope this helps, Organoman.

You’re not gonna know for probably 3-4 weeks from sprout. Go ahead and hit it with 18 hrs it will not be the cause of herming. You should see pistils/preflowers on an auto at around 30-40days after sprout.. where as a photo won’t do that until 6-8 weeks in. After a week of seeing pistils - an auto will start to have lots of them build up around the bud sites and show more signs of flower where that won’t happen with photos until you actually flip. Tho like I said around 6-8 weeks in - a photo will show two pistils at the nodes as a sign of sexual maturity

No their is no way to know until it either automatically flips or does not. As long as you don't give her 12h or more of darkness you can change the lights how ever you want. Only thing you can do is if you have the room then grow her out and see if she automatically flips( usually between week 4-6) and if she does not then flip her and enjoy the huge harvest. Happy Growing