I don't know how much you can trust the 12/12 light cycle. I have a feeling that plants start flowering before that. I live in Lausanne, Switzerland and 12/12 starts here on the 25th of september. However my plant has been flowering for 5 weeks already and will probably be ready for harvest before the 12/12 even starts, which is still 4 weeks away from now. I'm a first time grower so I don't want to make any blunt statements but maybe a 13/11 is enough for flowering. I think dropping temperatures play a roll too. Plant looks good tho! That's what mine looked like at the end of the first week of flowering. Cheers!