in most cases yo would cull the smaller ones. But you say a 10-12" bass weighs 12 oz. That is 100% relative weight. So I wouldnt think that they dont need to be culled. What size range of fish looks the skinniest? Get us some more catch data and measure and weigh them exact. I use a Gram scale because its a little more accurate. In a 2 acre pond you shouldnt have to cull many to make big changes. 50 bass could change things alot. What kind of forage do you have?