Hours of llight???

I've had a plant growing sense mid-march averaging 17-20 hrs of light from a 68/300 watt CFL. Its starting to grow rapidly and is showing sign of its sex. When should i decrease the hrs? and should i lower the watts? I own a couple 40/150 watt CFLs as well, should i switch or just add to the exsisting light??

If anything, add more watts.

add all the light you can with a CFL grow, I try to get at least 200 real watts of CFL around each plant for a decent yield. You can send them into 12/12 now if you want cause they will stretch and double maybe triple in size during flower.