We have had our inground pool for about 6 years now, and a couple of years ago it rained so badly that the liner actually started floating a bit. In the past when it's been very rainy and wet and we could see new wrinkles and bubbles under the liner we'd just leave it alone and eventually the water in the pool will press the water under/behind the liner back into the ground. This has been noted in other posts. However, over the past couple of years, when the water under the liner was forced back into the ground, it left wrinkles, and each time this happens since it seems the wrinkles are getting longer.
Now I'm getting water behind the wall as well, so badly that in one case the liner popped out of its track (kids could've done it too I guess)--my question is, HOW DO I GET RID OF ALL THESE STUPID WRINKLES ON THE BOTTOM OF THE POOL NOW, and why am I getting water behind/under the liner anyhow? Shouldn't it have been sealed before the liner went in? I'm almost ready to vacuum out the water from behind the wall, but figure I'll wait for it to seep back into the ground too.
Is it just time for a new liner? Thought they would last longer than 6 years...
Thanks in advance.

Sounds like your installer may not have check the water table in your area. What's going on with your pool is that after a rain storm the ground water pressure equals the pool pressure and the liner will float like it was in space. The liner may have stretched and the only way to reset it is to drain the pool and install a check valve in the bottom of the pool. When the ground water increases the valve will pop open allowing the ground water to enter the pool when the pressure is gone the water pressure in the pool with close the valve. Once this is repaired you will need to seal off all outlets and inlets including the skimmer and use a shop vac to re seat the liner and stretch it out. Once the liner is back in place you will leave the vacuum on until the water level is 18 inches deep in the shallow end. Then you can turn the vacuum off and continue filling.