I have wrinkles in my liner that have progressively gotten worse over the last 3 years. When I noticed the first wrinke, I inspected it thoroughly to see if there was any puncture in the liner that could have caused it. I didn't find anything. It got worse later in the summer so I had our pool co come out to inspect it. They come out with scuba tank and spent a long time inspecting and also did not find anything. Suspected ground water. Now I have wrinkes all over the pool (shallow end and deep end). I recall when we first built the pool, our builder said that chemical imbalances can cause liner wrinkles. Our fill water is extremely hard. I typically have around 40ppm alkalinity, 500+ppm hardness and keep the PH at 7.5-7.6 all summer. I'm concerned about whether or not the low alkalinity and extremely high hardness could be causing the wrinkles? I don't think it is groundwater related because we've never had this issue in the prior 15 years of owning the pool. This liner is abut 8 years old and is the thickest gauge liner that they offered.