Newbie here, and very interested. Honestly, this is the first I've heard of doing 12/12 photos, but it makes sense. Interesting that it works, though "how well", that is the question. So great topic and thanks for all who've contributed. You've got me wired on the topic now.
So I checked these other threads, too, and thanks for them.
https://www.autoflower.org/f2/autoflower-v-s-12-12-seed-4366.html
From this I get that it can take the 12/12 photos longer than autos, and maybe with less regular results. And caution against doing 12/12 with autos.
https://www.autoflower.org/f2/auto-vs-photo-12-12-start-17824.html
I'm getting more of the same from this thread, though some photos do well with 12/12. Some recommend vegging photos a few weeks first before 12/12.
https://www.autoflower.org/f5/what-would-12-12-light-cycle-do-auto-15333.html
Some conjecture on different photo strains doing well with less light. Interesting.
http://www.rollitup.org/indoor-growing/416589-12-12-seed-thread.html <-- over 1000 pages
This last one will take some work. Over 1000 pages!
Anyway, all good stuff. Wanna try it all!
