What dries out a liner?

[carlscan26]

I'm replacing my liner after only 6 years due to extensive sun rot. Apparently the UltraMayd liner's only advantage is that the warranty does cover sun rot so I might be able to see a 50% pro-rated savings on the retail (what the installer pays) for a replacement liner.

My new installer says that three things contributed to my liners early demise: 1. too much sun, 2. the liner was stretched too tight, 3. my use of liquid chlorine

As they were removing the liner today there were some sections that crackled and cracked apart - he pointed to these as being due to my use of liquid chlorine. I've been an adherent to BBB and the TFP way since I bought the house 7 years ago and since this liner had been installed I've only ever had to SLAM twice and that was only to a level of 12 ppm FCL for about a day both times. I use a pump for normal dosing so it's well diluted, and when I do add chlorine by hand I always brush the water around and use a wall whale to make sure I get good mixing with the water.

A different installer told me that fading (and drying) of the liner was caused by pH imbalance. I will admit that I haven't been great about pH management in the last year and it seems like the liner really faded a lot during this time. Don't judge - I was pretty bummed when I realized a year ago that this liner was shot and i lost a lot of motivation to keep it balanced when we weren't using it.

But my new installer insisted the crackling is from too much chlorine. Mind you, there were no tears or sun rot in the sections that were "brittle".

And even better is that his pool school which I am required to follow for him to honor his labor warranty is to use DiChlor (first mixed in a bucket) and a PoolRX device Needless to say I'm not super happy about these claims or his recommended process. Sticking with BBB won't void my liner's warranty; just the labor warranty that he provides.

But the question still remains for me - was the brittleness caused by chlorine or pH mismanagement or something else?

 

[borjis]

pH mismanagement can certainly shorten the life of certain pool components for sure. Liner's, heater's, etc.
If it lingered below 7 and lower for an extended period, that could have drawn a good chunk of service life out of it.

If you pour bleach into the pool over a deep end return jet to disperse it quickly, I just don't see how that
could possibly do any damage. How was the cya level at this time? Chlorine is harsher without it, but
I can't imagine you had it too low or zero in your region.

Interesting about the liner being stretched too tight. My new liner was installed "very tight" in the shallow
end, but the manufacturer stood by it (it was measured and custom made) as far as the warranty goes.
That part has to be on them.

Too much sun seems a bit odd for something that is meant to be exposed to the sun.

I'm not an expert but I'm going to go with PH being the main cause.

 

[carlscan26]

My pH would drift up - I've played with the calculator and at or above 8.6 it gets me to 6 or above for the CSI which is indicated to be harsh for all pool surfaces. I target my CYA for 50 given how much sun the pool gets. Apparently that top edge of the liner along the bead that isn't "painted" with the pattern has less UV protection and they expect the overhang of your deck to protect it. I've got an acceptable overhang as per the installer but the side of the pool with the su rot issues gets sun for all but the last few hours of the day so there's no practical way to shade that. I am considering hanging a sail shade but the primary driver is to provide shade for us not the liner.

What was your issue that they had to stand behind? It looks like we have very similarly sized pools - mine must be a bit deeper.

 

[duraleigh]

Long time no see! Stop by more often!

UV from the sun will damage almost anything plastic......but only above the waterline.......it doesn't penetrate effectively through the water.

If your damage is below the waterline, pH seems to be the most common culprit.

Your use of chlorine as you describe it has nothing to do with liner deterioration.

 

[borjis]

What was your issue that they had to stand behind?

When I filled the pool, the liner was stretched about 2 inches downward in 1/4 section of the shallow end wall.

It stretched the tiled diamond pattern and didn't look right, I was half expecting the liner to
pop out from the track. I sent a photo to them and they said yes it's a tight fit
and would honor any warranty still if there was trouble.

It's been ok for 2 years.

 

[YippeeSkippy]

Liquid chlorine doesn't seem to hurt the plastic bottle its sold in.

Maddie

 

[carlscan26]

When I filled the pool, the liner was stretched about 2 inches downward in 1/4 section of the shallow end wall.

It stretched the tiled diamond pattern and didn't look right, I was half expecting the liner to
pop out from the track. I sent a photo to them and they said yes it's a tight fit
and would honor any warranty still if there was trouble.

It's been ok for 2 years.

So that sounds like it was mismeasured... I’m watching mine fill right now - so far so good

- - - Updated - - -

Long time no see! Stop by more often!

UV from the sun will damage almost anything plastic......but only above the waterline.......it doesn't penetrate effectively through the water.

If your damage is below the waterline, pH seems to be the most common culprit.

Your use of chlorine as you describe it has nothing to do with liner deterioration.

I know right?!? I’m a bum!

The reason for the replacement is the extensive sun rot above the waterline on the two sides that get sun almost all day long. Basically the UltraMayd liner with its enhanced UV protection was snake oil. But it’s warranty may pay out so maybe I’m being too harsh.

The parts that crackled were below the water line. PH makes sense to me. Thanks all for your insights.

Now to convince the installer that I will be OK putting in liquid CL with my peristaltic pump...