Any Thoughts?

These plants have been veg for 19 days. They are in large 1 qt. containers. They would be bigger except I had some probs with super hard water, high Ph, which have been corrected. I was thinking if I dropped them fro 24/7 to say 20/4 the shorter photoperiod should get them to show sex. I cold then get rid of males and move rest into larger containers. Or I could just leave them in these containers and only veg for say 2 or 3 more weeks, thinking the containers should be adequate for that. Any thoughts?
Best Wishes
CD

Very doubtful they would show anything if you switched cycles. From my understanding a 12 hour or less cycle triggers a hormone release that starts flowering, not just any decrease in light hours will work.
They look good though, I would keep on veggin'