Don, you thoughts might very well be correct. Unfortunately, nobody that I know of has had any good long term success with Bentonite. If it's incorporated into the soil while the pond is dug, and then compacted, then the results are much better.

I have a ground water pond, in sand, and I'm afraid that I will have to drop a large well this year just to keep the pond full.

The willows do suck up a lot of water, but I haven't been able to find a reliable figure on how much per inch of tree trunk diameter. I haven't seen any comments on cypress.

Salt is used to help keep fish healthy during transportation, and a little is a good thing. What is the salt content of your well water?

I wish I could be of more help.

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3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).