You would get a lot better outcome if you use the hps for flowering. That is if you can keep the temps in check. Your plants will double almost triple in size(strain depending) so flip when you feel ready. If you decide to stick with cfl, i would personally add a couple more for some extra lighting. They will love the extra light during flower. Be sure to feed bloom nutes during this time. Low in N and higher in P and K. Start off with about 1/4 to 1/2 the recommended dose and work your way up. I personally dont do the 24 hrs of dark before the switch but doing so will not hurt anything. So all your call man. Good luck.