Pouring bentonite on the surface is a waste of time. Any wind or wave action causes it to wash to the banks and settle there. If there are springs at the bottom, I expect the head pressure from the pond is causing them to flow backwards into the aquifer.

The only thing I have heard about ESS-13 is the price. Pretty rough. I would contact them and talk though.

It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP Grandpa