What was the pH and TA at closing?
Probably groundwater pushed the liner up and the wrinkles happened as the water retreated and the liner came back down.
Do you have a picture?
Not enough to wrinkle the liner.
Low pH wrinkles are typically very small, very random and they would be everywhere.
Low pH wrinkles look a lot like this.
Please excuse the delay, I wasn't aware that you posted a reply. I'll have to see if email notification is an option here.
Since the new liner was installed, I make sure the PH is at least 7.8 and the TA about 80 when closing. TA always remains around 80, so never had the need to adjust it. PH can fluctuate sometimes, but mostly after a day of swimming with several family members. It was the end of the season when the new liner was installed, and the PB added CL and Borax to the water he supplied. 2 weeks later I closed the pool. At this time, I was still using dip strips and the pool store for testing...yeah I know!! Old school mom & pop kinda place, so had -what I thought- was reliable results. Just prior to closing I had the pool store test the water, and as I recall everything was fine. At that time, I also had just discovered TFP and decided I wanted to do my own testing based on what has been said here. So starting the next season with a new liner, I have tested the water myself using the newly purchased K2006. When I opened the pool for the first full season the following year, that was when I saw the wrinkles.
I question the ground water being the cause as I am located on a hilltop...high and dry. Never any standing water anywhere in the 30 years I've lived here. I've dug 6' deep holes and several trenches and never any water. When the pool was dug (8' @ deep end), the hole remained dry the entire time except for rainfall. When it did rain and the water collected in the hole...it was bone dry by the next day. Not once did it require pumping. If it was caused by groundwater, wouldn't it just be limited to the pool floor and not the wall? Behind the deep end wall where the wrinkles are, had to raise the finish grade about 2' or so. So we used the material from excavation...sandy gravel type of fill.
I have a few pics of the wrinkles, but here's the best one at sunrise with the pool off and the bright sun. You can see the vertical wrinkles on both sides of the light. No where else are they're any. I did wonder if the wrinkles were a result of draining the pool down just below the returns for closing. The same way I had done it all the prior years with the original wrinkle free liner. I actually wondered if the wrinkles were due to something??? from the liner installation.
My question is...Is a cover absolutely necessary if you have no trees around whatsoever? Is there another purpose they serve other than keeping stuff out?
