damn, if this is your first grow mabey you should start smaller, especialy if it is for a dispencary, you are talking about a massive grow op. I say you need go with 1000W lamps and many of them, hydro or soil what ever is easier for you, and you are gonna need help, because tending to that many plants is alot of time and labor. mostly at harvest, but for that kida of grow, a house in a good neibor hood, if you are using CO2 then you need an isolated house out of the city. wow 15k expected yeild thats alot

time frame is differant, for every strain, biggest is Indica or sativa ( sativas finish late; indicas finish early, late being in Nov, early being in Aug/ Oct, then it gets a littel differant in between phenotypes, from seed to harvest is any where form 2- 8 months. everything from plant size to environment have to do with time frame