ive been using tents of that size since i started growing and ive went with 4,5 and 6 plants in them . in soil , under 400, 600 and 1000 watts. if your wanna grow naturally, ie without lst, supercropping , topping , lollypopping etc then 4 is best, if u want to lollypop then 5 is fine , 6 is too much, they just light block each other. if you wanna scrog then its a different ball game again,if u wanna go 12/12 from seed then once again it all changes. im gonna assume your a noob here so sorry if im patronising but my advice is go with 4 and let them go totally natural, it'll teach you a shit load you wont read about, there is NOTHING compares to hands on experiences. start your seeds in 1 litre pots, then up to 3s and finally 15s. the tent is big enuff for that. veg them till there no bigger than 2' or you could get a shocker when sum fuckin monster wont stop growing, theses fuckers can treble in size and do so regularly so unless you wanna snap a big main cola or cut a hole in your tent go on the side of caution. best of luck buddy.