Bruce Banner

Unfortunately, it is one or the other. Your fem plant will not flower under 20/4 and your autos won't perform very well under 12/12. In my opinion, 18/6 is far more plant friendly, cannabis can only grow so much during any 24 hour period and that growth tops out at about 18 hours, therefore running your lights for those extra 2 hours will result in very little extra growth over just 18 hours and is basically a waste of electricity running your lights for 20 hours or more. 18/6 light schedule has been arrived at at over 80 odd years of research, with all experiments coming to the (more or less) same conclusion. Plus, your plants do need a "sleep routine" whereby they conduct certain metabolic processes during the dark that they can not do during the light cycle and I believe 4 hours is not quite long enough to do these things. I like to think of it as; 2 hours to wind down, 2 hours to repair and 2 hours to get ready for the next day. Also, I am not going to argue with the evidence from 100s of experiments. Pushing plant to produce like machines is not what growing is all about in my opinion. Anyway, you have 2 choices regarding your plants, sacrificing the growth of one or the other or putting one or the other(s) into a different grow set up if you want to maximise the harvest from both types of pants. Really, there are no other solutions. Hope this helps,.... Organoman. .