Lights on lights off

12/12 will slow your auto plants down and possibly result in smaller flowers. It seems most auto growers have settled on 20 on and 4 off as the easiest compromise. I believe plants do require their rest and lighting at 24 on constantly, or 22 on 2 off is just too much light and not enough recovery/sleep time. For the second part of your question, that is a very interesting one! I believe plants are producing energy and adding growth slowly during the day(light) cycle and seem to put most of the noticeable extra growth during the night(dark) cycle. I am basing this on outdoor growing, so am open to opinion, however, I have noticed little change in plants during the day, but when you see them in the morning, changes/growth seems to be more identifiable. Then again, during the day you generally see your plants more often and growth may be harder to detect compared to night time, when you do not see your plants for a longer period. I think I have just found a new experiment to conduct! At this stage I believe plants put most of their new growth on at night time. Hope this helps... Organoman. What do other growers think about day/night growth?? I think you have opened a can of worms here Dean1!!!