Pond Boss Forums POND CONSTRUCTION Soil questions Bentonite first...Now a Sealing Polymer...?

Good point, and if the product worked that way, it would be a concern. However, the product isn't designed to act as a liner or blanket, rather it enters the fissure as water escapes through it and carries the linear and crosslink polymers where they expand and seal. The fissure is stopped below the bottom/side of pond - it's not a blanket like you're thinking. If a pond is entirely permeable and holds no water whatsoever, I don't think this treatment would be effective for the reasons you cite.

Product can be applied during construction [dry] or after [wet]. The biggest benefits are that it's non toxic to fish, can be applied to full pond, don't need to drain seine, dry out and spend thousands on reconstruction, and it costs a fraction of ESS 13.

I don't know how long the seal lasts,and that part does concern me. However, for the minute amount of product I needed to treat my pond I wouldn't mind applying it annually if I had to - I'll still be way ahead using the well. I will be saving myself millions of gallons of water and thousands in electric bills pumping water into that formerly leaking pond over the next several years. For the price and ease of application, it was definitely worth the effort and cost in my scenario.

Can it be used as a "liner" for some sieve of a gravel pit? I don't know, but then again I don't think anything will fix a pond like that - it just shouldn't have been built in the first place, probably.