If you keep your temp down, and veg. plants to a decent size since you wont be doing many plants. Either way you should get AT LEAST about .4 G/W of dried bud. So a 600w with 7-9 plants should yield 8 oz. Unless it is like regular genetics or somethn. Any kind of chrons should get you at least 3/4 to 2 oz per plant. i did a 600w 3x3 tray and 25 and got about 15 o's. that was hydroton medium, ebb & flow setup.