From the beginning I kept my sprouts on a 24 hour cycle. I was feeding them the Cutting Edge Solutions at the proper mixture and the plants didn't seem to grow very much at all. I'd heard about 18/6 cycle and recently even a 14/10 cycle. I kind of ignored it until a friend of mine who is an amazing grower (if you see my first grow, the two taller plants are his indoor purps) said that plants need a resting period, and I had read they still absorb nutrients and grow better.
I recently switched to an 18/6 cycle and the changes were immediate. I now have 3-6" plants which I believe are already showing sex and the majority seem to be female.
Going on with the rest period, I read earlier a 14/10 will increase your amount of females, as well is increased nitrogen in the cycle, and keeping the room temperature perfect as well as the right humidity. Given the perfect growing situations you "may produce over 90% females", and I say this in quotes because I'm not claiming this is true.
I will be testing the 14/10 cycle with my smaller chamber, I'll let you know how it works.
Of course my increased growth could have been changes to better lighting, or adding Root Organics to my mix, but know that it's obvious that the right situations will propel growth. Also they have very nice roots and strong firm stems.
If of course you want to slow growth, maybe a 20/4 or 22/4 cycle may slow growth but still give it a resting period? Just a theory.
And on second thought, maybe it's good to go 24 hours first until sprouts appear with a leaf or two then switch to 18.
