i agree hermie. joel his current cycle is 16/8 so changing their light cycle to 18/6 will not make them show sex. what i would do if i were you is take a cutting from each plant let it root then put that in your flower chamber, now if its a male you know the plant you took the cutting from is male if its a female then you dnot have to revege that plant to get it to the desired height until flowering, or you can keep whatever turns out to be female as a mother and clone the shit out of them. when you do it like this you dont lose much time from having to revege the main plant and taking one cutting wont do shit to the main plant as far as shock goes.

thats what id do, you really dont want to start from seeds every time or you will only get a few crops a year

-secret