thats a hard question to answer. depends on growing style, i got about a half lb from a single plant in a 2x2 scrog with 300w of hps lighting and 125w cfl on it. could have been more with a bigger pot like a 15gal and better lighting. and that was with reserva prevada headband indica dominant hybrid.
There are alot of variables; strain, lighting, nutrients, temps, training, topping, ect, ect and experience. If I remember right you should average 1 g a watt.
So I guess what Im asking is, is it possible to grow a pound in a tent that size under a 600w? I want a 2x4 so I can conserve space but Im also looking to get at least a half a pound every 3 months. If I were to get a 2x4 and a 600w hps digital ballast bulb what would be the best method to getting over a half under 3 months time? Considering its a perfect Indica dominant strain for the job.
You have two main options.. A few plant scrog or a bunch of plants and do a SOG. The SOG will have a quicker turnover time but will require mother plants and lots of clones as well as the potential to get caught with a lot of plants.. I would go with a scrog and 2 plants in hydro under that 600w. To get a hp your going to need to have everything dialed in right; temps, RH, possibly co2, good light...
If I were you, I'd go for a 2 plants scrog. With only this, I'm thinking a 6-8 week veg and 8-10 week flower for approx. a hp every 14-18 weeks (every 3.5-4.5 months), but could be just 8 weeks with a faster flowering strain and a separate veg space....I know you're tempted!!!
I have a 3x3 tent with a 600 hps and do 5 plants I average 2 1/4 oz/plant. My personal best was 15.5oz total from a 3x3x6 tent