"per plant" only counts when your doing sog, when every plant the more care and more gram it grows your gaining 1 gram per plant so if your growing 448 plants and with extra care is giving it a extra gram your gaining 1lb. That being said is harder done then said, a average person that does everything he knows will yield about 1.5lb per 1k lighting thats about .6-.8gpw, but if your good and you know what your doing everything goes perfect you will yield about 1gpw or more which is average 2lb per 1k lighting which isn't proven much, but isn't practical.