I've grown lots of 6-foot sativas in 8" clay pots (I didn't know any better, not advisable) ... the larger the pot, the better the yield, plus more efficient watering and feeding ... I now use #5 pots (typically called 5-gallon) ... you 'may' hear comments that you should start in small pots, and transplant several times into slightly larger pots each time, rather than going to a big one ... FALSE, another urban myth that doesn't hold up ... (outdoor plants would have TOO MUCH growing room ?? I don't think so ) ... good luck with your grow ... :smokin: