Light cycle for fastest (flowering) clone re-veg

Agreed, 18/6, but don't expect it to happen very quickly, and in my experience, it is very hard to do and not all plants will do it. Trying to successfully clone a plant that is as advanced in flowering like the one in your picture (the left one?) is extremely difficult. By the time they revert you could grow some healthy and well established seedlings, from seed, in the same amount of time. I am not saying that it is impossible, but growing seedlings would just be easier and no doubt, a lot faster. Hope this helps, Organoman.