I stocked my 3 acre pond last year, 1000 bream per acre along with Fathead minnows. I added my bass A few months later. The fish are growing well (length) They are 9 and 1/2 inches long but only weigh about 4 oz. The pond was really low during the summer, so we dug some extra ditches for depth the water became real muddy. Could that be the problem? How can I get the weight on my fish? I tried real hard to get things balanced from the start, but it seems things are already unbalanced. You can visibly see that the fish are skinny. I also have several blue herons in the area, can the eat enough of the minnows and small bream to alter the food chain?