Hi Weedhound. Thanks for the advice.
I'm getting kind of contradictory advice with regard when to determine sex and when to move to 12/12.

Some have recommended waiting until pre-flowering has commenced before switching to 12/12, although I take your advice on sexing the plant in the 12/12 period to be absolutely sure, prior to "culling the herd" (can the leaves of early, culled, males be used to make hash?).

Reckon I'm going to wait a couple of weeks yet, although my plants are getting big now in a small space.

Coulpe of questions that have arisen from the responses I've received though:

1) I am at week 7 from seed and was expecting to have to keep in the veg stage for at least another couple of weeks. Can you pretty much move to 12/12 whenever you like? I assume that the younger the plant, the lower the yield and/or strength of the yield? Some of the pictures on here it seems that people are moving to 12/12 within a few weeks on really quite weak looking plants. Is this just impatience, or just a desire to keep the time-scale down?

2) I've got a 200W red spectrum envirolite for the 12/12 period. Would it do any harm keeping my 200w blue running as well? I don't want to run it if i don't have to but if it might improve things in any way, I'd consider keeping it in.

Thanks again. Sure appreciate the advice.

Chester Atkins
Nashville