You can flower your plant at pretty much any time. It all depends on how much grow space you have, and how big you want to grow the plant(s). Usually in flowering, a plant will double or even triple its size, so keep that in mind. And yes, you can put your plant into flowering to sex it. It should show sex between 10 and 14 days of 12/12. At that point, your options are numerous: you can grow it out, take a cutting or two to put back in veg to keep as a mom, etc. etc. However if it was me, I would let the plant grow big enough in veg to take a nice cutting or two, and as soon as the cuttings rooted, I would flower it (or them) to determine sex. Hope that helps....Hello, I have 10 day old plant that is looking great, have about 90 watts half 2500k half 6500k, but I only have ONE. bag seed, so i'm wondering when you guys would 12/12 it to sex it and if I can turn it on 12/12 , sex it, then turn it back on veg - 24 hours a day light- thanks