those babies need bigger diapers if ya want em to grow into women

seriously though, that's really rootbound, i suggest a repotting, it'll delay your flowering by a few days but it'll be very helpful in the end.

if you've already got them on 12/12 then keep them on 12/12, never go from 12/12 back to 18/6 , it'll mess with the sex of the plant. as for your ferts, i don't see any signs of over fert... if you begin to see signs on the leaves... cut back.

overall, very healthy looking plants, i can see you've done some reading and know at least the basics of growing.. well done.

although they are small for their age, they're not done yet. get em into bigger pots and you'll see a very large increase in size..
but don't forget, larger pots = larger plants = more space = more light = more heat = alot more things to think about..

... put that thinkin cap on :P .. i know you own one.