How much square feet per marijuana plant

A question from a fellow grower:

10square feet of plants, how many plants is it ? Is it 1 square feet per plant ? Also 9-10 plants ?
And how many watts og HID light you need in order to get about 20 oz ? 400 -600Watts ?

Maybe this will help. Maxing your yield can be done with a sea of green, maxing out the number of plants for your room, but you can get the same yield or even better one with one plant trained so that it has many tops filling the canopy’s square footage in a screen of green. Check out this link as well as other guides under “inside grow” and if you have more questions and more info about your desired grow please come back and let us know.