1 Gram per watt and you are officially a Pro. You should really be shooting for .5 grams per watt if its your first grow.
If you grow well.... There is no reason you cannot yield 2-3 oz on 4 plants under a 400 watt HPS. I generally get 2.5-3.5 oz per plant. Veg them until they are 24 inches high then flower them. HPS does not cut down flowering time compared to CFL's, it just makes better and more buds.
My experience: I got 25 grams per plant flowering with a 400w using coco peat as medium. But it is possible to do double that.
yea its not anout how many plants. with my 400, i was able to pull a qp really regardless how many plants i grew, one plant = 4-5 ounces when i vegged for 3 months. 4 autos gave me 4.5 ounces. and i once did 6 autos and got 4 ounces. i think its all dependant of your light and size/quality of the environment.
http://www.rollitup.org/grow-journals/350285-my-first-grow-purple-wreck.html please check out how my plants look and give me some advice on my light set up. im currently vegging under 400w HM lamp with a vented hood. they are month old clones. i plan on getting them to 20" and flowering them under 1x 1000w Hm 2x 400w MH all warm/red bulbs. any advice would be greatly appreciated!
