Little bit early. The 2 little green bits at the fork of the leaf should put out two little white bud hairs if female or if not 2 little balls if male.
Just a quick question on the header tank. have you got a air stone in it. and are you watering at least once at night. Not watering perlite for 4 days is not good. your not aerating the roots
running cost and buying cost was the big reason i 'm choosing the COB. also i've tried LED's with the veg & bloom switch with not much success. also tried just white light,bit slow in grow. the combination of led's and the cree's (for the extra spectrum) and the extra coverage makes good sense
i'm not to bad at the SOG under hps. best i,ve got is around 3 and 1/2 lbs from one plant.(super iced grapefruit not hard with this variety) very keen to get perfect suns COB going to see what i can do under led.