Wrinkles in vinyl liner in in-ground pool

[poolmama]

About 3 years ago, we started getting wrinkles in the bottom of our vinyl liner, first started in shallow end and now are in the deep end. We have concrete under our vinyl and our vinyl liner is about 10 years old--it still looks great except for the wrinkles. I use borax, baking soda, and the tri-clor tablets for maintenance. I don't believe I have a leak as the water level doesn't change much. I have always struggled keeping my ph up and go through a lot of borax. Last year I really tried to notice when a new wrinkle appeared. I keep a solar blanket on the majority of the time when not in use as I like 84 plus degree water and sometimes our pool temp gets 86 to 88 during July--I usually can go a couple of weeks in July without the solar cover. It seemed that wrinkles would appear when the solar cover was on. Could my ph be causing the problem?

20 x 40 vinyl liner, concrete underneath, IG, sand filter 30,000 gal

 

[waste]

Re: Small crease in vinyl liner in in-ground pool

Welcome to TFP!!

(I'm gonna ask the MODs to separate this so your issue gets the full attention it deserves )

How do the wrinkles look? (a pic would be GREAT!)

The low pH will wrinkle a liner - actually, it's more like 'puckering' when localized. What might be happening is that water is getting betwixt the concrete floor and the liner and floating the liner - are you in an area that has had heavy rains the past few years?

Again, welcome here - I'll get you your own thread for this and see if you don't draw more answers

 

[Bama Rambler]

We've gotten some wrinkles in our above ground but I know the rains coupled with our gorilla bottom caused them. Hopefully that's what caused yours.

 

[duraleigh]

Can the low pH be causing the problem

Yes. The low pH is very likely coming from the use of pucks. I would also not be too surprised if your CYA is very high unless you have been draining to compensate. Can you post test results?

 

[abgal-australia]

Hi - I work for a vinyl liner manufacturer in Australia. Duraleigh is right - your problem is most likely the low PH. A PH of 7.0 or under can actually cause a liner to 'grow'. Once it has grown and wrinkled, there is no shrinking it back. For a vinyl liner PH should be kept between 7.4 and 7.8. Less than that your liner can become soft and 'wrinkle'.
Cheers.

 

[frustratedpoolmom]

Keeping the cover on for long periods can also cause the PH to drop - so if you've been fighting to keep the PH above 7.2 then that's likely the cause of the wrinkles.

 

[waste]

Hi - I work for a vinyl liner manufacturer in Australia. Duraleigh is right - your problem is most likely the low PH. A PH of 7.0 or under can actually cause a liner to 'grow'. Once it has grown and wrinkled, there is no shrinking it back. For a vinyl liner PH should be kept between 7.4 and 7.8. Less than that your liner can become soft and 'wrinkle'.
Cheers.

Welcome to TFP!!

It's always great to hear from the industry folks on issues

I'm going from 20+ years of seeing pools with this issue, and (as far as I can tell), the liner is OK as long as the pH is at or above neutral (7.0).

Localized issues, like dry acid was dumped in one area or a tri-chlor puck was left sitting in one area too long, causes the 'puckering' I spoke of ...

Generalized weakening of the liner happens if the pH is maintained for an extended period, resulting in a brittle liner, but not areas with wrinkles

Mayhaps, I just haven't seen it all