I went cheapo this time with LLDPE liner. I don't like it. Very hard to get the folds smoothed out. But should last my lifetime. The original liner lasted over 20 years, I want to say it was PVC but don't really remember. I did not change the structure of the pond. I bought a 20x15 ft liner as I couldn't find a 20x10. I also bought those "liner blankets" to keep those pesky roots from puncturing the liner.I had a pond built during the front drive rebuild and rear patio renovation (i.e. it was collapsing), so had to have a chunk dug-out and rather than fill it in, it became the start of a 7m x 2.5m pond! I got them to use the same tanking material (some kind of waterproof cement) that is used on cellars, basements, and lining water-tanks (so non-toxic). Its working really well and worked out about half the price of neoprene pond liners.
I have finally learnt not to do mechanical or building things, as it costs me a lot to do it, and then twice as much to get somebody in to fix it by doing it properly!
This time I had to do it all by myself, as my wife has COPD and can't do such things.
I hope in about two weeks I can get some fish back in the pond.
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