Scsims.You should search this topic on this site.It will provide info on bentonite {sp} clay. See an article in Pond Boss last winter on the topic. Oil and Gas drilling companies use drilling mud which is made up of water and bentonite clay. The clay is dry in bags . We fixed a pond that had a stray sand that was leaking by adding several bags of aquagel {that is what the powdered drilling mud mix was called}. One application stopped the leak. I hope this helps.Ewest