How long has this plant actually been showing signs of flowering? Not when you put it under 12/12 lights.
I definitely think it needs quite a bit more time. The buds don't appear to have swollen much yet. I would honestly guess 3-4 more weeks but that can depend on alot of things, but primarily it will depend on genetics. According to the description it says 8 weeks which can vary depending on phenotype also. I don't start to consider my plants to be flowering until I see signs of flowering. This can be controversial some growers count from 12/12 others from flower signs. When its all said and done looking at the trichomes on the plant is gonna be the only accurate way to judge the maturity. You can get a little scope with 60x magnification at radio shake for about $10. Look at the trichomes on the buds at the top and bottom of the plant. I harvest when it seems that 90% or more of the trichomes are completely white/cloudy(maximum THC potential) and I have some ambers as well to ensure full maturity. Some people wait till they have a higher % of amber to increase the sedative type effects by letting some of the THC turn to CBN(which is why it turns amber).
If you are going to flush most people flush for between 1-2 weeks. I always suggest that new growers try both methods at some point for them selves to determine which they prefer in the long run. Some people don't believe in flushing, some swear by it, personally I don't believe either group is right or wrong, just different. I've tried both and I don't flush any more it never seemed to make a difference.
However the way that you dry and cure your end product will make a HUGE difference in how it tastes and smoke!!!!
Anyway I touched on several points here, but I strongly suggest READ AS MUCH AS YOU CAN about all these subjects. Please be careful what information you take at face value, and do your own research and experiments. Far too often you get people just parroting information they have read without ever trying any of it, or actually comparing things. There are MANY different ways to grow so never stop trying to learn!
TC