After just sort of 5 weeks at 18 hours light, the photoperiod RQS Mimosa plants are at 16". I'm starting to worry about the 'stretch' of the sativa plants will grow too close to lights. So I switched to 12/12 at this time. Started the Fox Farm flowering nuts about this time as well. Photos here are bit into week 5... but wow now we can see the starting of the flowering, so cool.