ok, here we go again. i was saying that if you can leave them outside, i would. it would only take an extra month or so compaired to bringing them indoors and putting them under lights, if they are mature enough to flower right now. it has more to do with maturity than how big they are. you can start to flower earlier, but right around 8 wks old you should be able to see preflowers or alternating nodes(meaning maturity) then consider it will take about another 8 wks to fully flower under 12/12. the sunlight will be better than any light and also give another month of growing time(bigger yield). heat and bugs could be a problem bringing them indoors during the summer. why not wait untill winter time to try growing with lights, and either take seeds or clones from the plants that you are growing this summer. does that about cover it? lol. as far as lights go you would want a hps for flowering. a 400w hps should cover about a 3x3 area or 9 plants in 12 in. pots.(5 gallon buckets are about 12in. across) some would say less plants, but i would cram them in. no offence taken. i had a few beers.