I am a new inground pool owner and we have high groundwater where I am. I moved to my house in the fall and opened my pool this summer and there was a lot of water under the liner. There is a pump installed and I pumped out the water and liner went back into place but it ended up tearing in a lot of places (old liner). I assume because it was an old liner, it was more brittle and couldn't stretch as well back into place.
I will be buying a new liner and was wondering if a thicker liner would be better (27mil) or should I go with 20mil. The groundwater is my main concern - I will pump as much as needed but I am afraid of running into issues again over the winter. I guess I will just have to pump throughout the winter also to keep the groundwater from becoming a big problem. Would there be any reason a thinner liner would be better or would it be safer to go with the 27mil? If groundwater does get under the liner and has to be pumped out - which would stretch the liner back to where it should be - over time this will probably wear the liner quicker I assume? Is there any reason the 20mil would be better in this situation or would you recommend 27?