I wouldn't even know where to start. I can say that if you don't know where the leak/seepage is, then you would probably be wasting your time applying bentonite with the sprinkle method. And as far as I understand, there is no current method/device of determining where water seepage is occurring within a pond. Would be really nice if there were a device that could locate a leak and atleast get a person in the ballpark of where the seepage is occurring. Such a device would be similar to what is used to detect holes in pool liners.