if it is wicking, once saturated, it would stop?
First I am not a professional and so this is not a professional answer. It is an opinion.
My opinion is, if a leak is big enough to cause erosion, it is VERY unlikely to get better over time, and likely will worsen.
If the leak is a seep, it may or may not get "better" or quit entirely. If sediment or clay in the water seeps through the seep area and deposits the clay particles, eventually (eventually being the key word) the leak could stop. I'm pretty sure that is what bentonite does. It is basically like radiator stop leak. It seeps into the leak clogging it up. Adding lime causes the clay particles to flocculate and settle out. So this could free up clay particles to fill the void area in a leak.
If I had a very small leakage amount, I personally would not get overly excited about doing a lot till I saw if natural forces clogged the seep up. Might take a couple years. Bigger leaks................. I will leave the opinions to the professionals.
Edit: one obvious problem with waiting a couple years to see if a leak seep type leak stops. What does a person do about stocking the pond if it is a new pond? Stock and hope the leak stops, or wait and see? Don't have an opinion on that one.
