OldMac, Ya you are right, roots grow in the dark period. I am not stating what I mean again.

The stopping of photosynthesis with the loss of light allows the plant to concentrate on the root system, which I believe grows a stronger plant. As any study can be made to show whatever is desired, it is all a matter of opinion.

I prefer to save the money on the shorter time as I see no benefit in the end result with times other than what I use....18/6 and 12/12.

We should do a whole thread on roots, because what you see above has someplace in the pot down in the dirt. And we thought the human circulatory system was complicated.