ASD - I am using two lights. A 400W is sitting over the taller plants and a 250 is sitting over the shorter plants. The lighting in there is kindof a pain in the ass b/c the strains have about a foot of height difference - there is a pic earlier in this thread. I like to count flowering when I first see pistils - not when I go to 12/12. The reason is - I have found that some strains take longer to show pistils than others. Some strains take a couple days - others take a few weeks. For some reason, these two strains started flowering about the same time - about one week after 12/12 - so I just started counting flowering then. I have found that counting the days of flowering when I first see pistils helps me get a better estimate of how many days the plant has actually been producing flowers - which in turn gives me a better sense of when they will need to be chopped.