Bruce I would also be interested in Bill's thoughts. I will say that a lot of (it all) depends on natural water quality. Here are a couple of examples. In 2 of our ponds we can run 500 lbs per acre with little feeding and minor fertilization and no aeration because of the good water quality and small springs. In the other pond with no springs and no fertilization and no aeration or feeding we have about 150 lbs per acre. In some places in Fla. (phosphate pits) with springs that flow through natural limestone into the pits (all natural) they have in the several thousand lbs per acre range with no feeding ,aeration or wells. I have seen underwater video of these pits and the water is so full of fish that it is dizzying to watch. Huge schools of shad , tilapia , BG , RES , shiners (emerald and golden) and minnows of many types along with LMB , gar and cats.