A year ago I built a 2.5 acre pond. It is very deep pond, around 25' at dam and 15' in the middle. A slow leak has developed and we lost around 5' of water. We stocked the pond with bass, bream and catfish. I have fertilized the pond and had a feeder running. I have seen great growth in the fish stocked. I do not want to drain the pond to find and fix the leak. Can you spread bentonite around the dam and hope it will sink to where the leak is or is that a waste? It is possible that the leak is around a pipe we put in through the bottom of the pond with a valve on the backside to use if we ever needed to drain the pond. This may be a silly question, but could a diver go down and put bentonite around that pipe? Any other suggestions? Thanks.