brings back memories of my first attempet at indoor, 13 metal halide 1000 w, big 48 ft by 32 ft steel building, 120 sativa planted str8 in ground, flowered in 120 degree temp, spider mites, white flys, good god what a failure, this was back in 1980 so i dident have the internet to learn from but belive me i learned the hard way. lol..Lol... Ambitious aren't you? I can't believe you're growing extreme sativas, and over 300 plants from seed for your first grow. Balls to the walls...
I'm sparing you the lecture about not being ready, cause it sounds like you're already comitted... So get some pics up so we can see what's up and help you out...