Ponds :

Sounds like you are off to a good start. BTW none of us are entitled to more than 3 days a year where everything goes as planned and I will settle for 2. One thing DD sort of noted and I can confirm about bentonite is that it will often mix with water and move toward the low pressure spot (leak area) and expand to seal the leak. That is a major reason (along with lubrication) that it is used in oil well drilling muds. I think you have a good chance that it will work. We look forward to tagging along with you on your pond journey via your posts.