How to judge when to replace vinyl liner

[LotusRacerX]

My pool is now in its 9th year, close to the liner lifetime. I have a couple of symptoms for your consideration:

1. "Squishy spots" in the deep end, on the angled portion just below the straight wall. You can feel them now for the last year or so.
They do not appear to be growing, are they pinhole leaks? Don't sweat it until the water level starts dropping?

2. Faded areas. One pool guy told me that my extremely low calcium hardness was leaching the color out of the liner. Some parts of the print are perfect, others nearly bleached white. I thought that the liner vinyl was chemically inert, and that was not really possible, but he sold me some calcium-up, to produce I think 75ppm of hardness, as a minimum level. Actual name on the tub is "EZ Clor Calcium Elevator".

Is the true test just whether or not you can keep water in the pool?

 

[JasonLion]

Liners can last far longer than 9 years, or fail before then. So don't assume it is time to replace the liner simply because it has been 9 years. Generally you keep a liner until it fails, ie tears/cracks too much to be easily patched, and then replace it.

Squishy spots are caused by the condition of the floor under the liner. Support material can be washed out by tiny leaks, creating that effect. Or the floor can become uneven as it compresses different amounts in different places, which sometimes causes the same effect. I would examine the area with googles closely to see if it needs a patch and if it looks fine ignore it.

Fading can be caused by several different things. All vinyl fades over time due to UV exposure, but high quality vinyl that has been well treated fades far more slowly than cheap or mistreated vinyl. CH levels in the pool have nothing (or hardly anything) to do with it. Several people here have had exceedingly low CH levels without problems. Still, there isn't enough cumulative experience to say if the effect is simply very slight or is non-existant. Because of that we recommend a minimum CH level of 50. But nothing obvious happens even when you go below that.

Fading and failure can be greatly accelerated by extended periods of low PH. Fading, and to a smaller extent failure, can also be accelerated by extremely high FC levels. Usually failure only occurs after truly extreme FC levels, while some fading due to even normally high FC level tends to become apparent after a decade or more. Very low PH can cause the vinyl to become brittle and crack very easily, leading to rapid failure after enough damage accumulates.

 

[LotusRacerX]

Excellent advice. Well said.

Funny thing about my fading is that it tends to occur in streaks. I have always blamed it on my Polaris "burning rubber" near the edges of the pool, where the fading is worst. I have an equal amount of "faded paths" in deep and shallow ends.
It goes from "as new" to "totally white" within a 6 inch span along the edges of the faded areas.

It is dark now, but I will see if I can attach a photo sometime this week.

 

[LotusRacerX]

OK, here is a photo showing my spotty liner. It seems white where people can stand, and also near the bottom of the hopper, where the robot transitions.

Did some research and found I have a Tara Manufacturing liner.

Tara has some interesting ground rules in their warranty: (A 20 year warranty! Although years 8-20 are prorated to 20%, and it only applies to seams splitting.)

1. Maintain proper water balance:
PH in the 7.2 to 7.6 range (This sounds fine)
TA at 100-150 ppm (a bit high, but not unreasonable)
FC between 1.0 and 1.5 (That sounds a bit low to me...walks the edge of too low)
Calcium hardness : 200 ppm minimum (This matches what, my pool repair guy said.)

2. Avoid using muriatic acid for PH adjustment. The acid will chemically attack the print pattern on the liner and will ,make it more susceptible to abrasion over time. Sodium BiSulfate is recommended.
(Worth noting that I only discovered MA recently since joining this site, and have used just 1 gallon so far. Now that I have added Borates a month ago, my pool has stopped requesting its weekly acid trip.)

So, any idea why my pattern is fading in blotches?

 

[JasonLion]

 

[Undrwtr1]

My liner is at the 12 year mark and has begun popping large areas of the bead annually (now have liner-lock in large number of places) and showing some serious shrinkage, causing some small tears at the point where the bead is seamed to the liner. However, it has been faded for many years, primarily on the bottom. When I called my pool builder about a new liner this week, I remarked to him that I was tempted to get a solid color. He asked if I had a Polaris and when I said yes, he said that they often abrade the liner and prematurely wear the patterns. In fact, when I put on my mask and look carefully at the liner, the pattern does appear to have been scratched away, rather than faded. A look at Polaris' 380 manual (newer one at page 1) even indicates that this is a problem. So, to answer your question, if the liner is in good condition, and you can live with the faded appearance, live with it (I did). If you hate the look of the fading or there is damage to the liner - replace it. My thinking when I installed the pool was that I would need a liner every decade or so. I got 12 years and I'm satisfied.

Gerry

 

[LotusRacerX]

Just now seeing this...lol, I have the Polaris 380 as well. I am thinking that he is the guilty party. Will give it a few more years.

 

[LotusRacerX]

Post Script:

Replaced the liner this past fall. It was suddenly developing small 1"-2" tears in the bottom. By 12 years, it was now nearly completely white, except for the part on the shady side above water.

Pool company confirmed the Calcium Hardness needs to be near 200. I had been running my FC at about 6, thinking that more was better. They recommend no higher than 3.

I replaces the Polaris with the new model with the fat tires, in hopes of alleviating the abrading problem of the 380.

 

[woodyp]

Calcium at 200 or higher is recommended for plaster pools------not liners. The pool company will ALWAYS recommend an FC level of 3. They fail to recognize the CYA/FC relationship that has been proven here.

 

[lillyvan]

I am still a novice when it comes to pool maintenance, but I have heard that living in an area susceptible to ground water problems can easily damage the liner in the pool. The groundwater table naturally rises with snowmelt and spring run-off and this can cause the deep end of the pool to flood when it gets pumped out for the liner exchange. Harsh ultraviolet rays, groundwater leaks, and the water chemistry can also affect the longevity of the liner. If you need to get the liner replaced. The best time to replace it would be in the spring as liners go in easiest when the sun is out and over 70 degrees.