Chlorine Levels and Vinyl Liner

[dschribs]

Because of my job (Insurance Underwriter) I was able to attending the Pool and Spa Show in Atlantic City earlier this week.

I'm shopping for a new liner and so this was a great opportunity to speak w representatives from the 3 biggest liner manufacturers/distributors in the country. My biggest concern about getting a new liner is fading - because mine has indeed faded after only three years. To be frank - I don't know anything about the quality of my liner because it was in the pool when we bought the house and it was not faded when we bought it.

Anyway, I asked each one of them how chlorine levels affect the fading characteristics of an in ground pool liner. As we know - the "standard" chlorine level in pools w pucks is 1 -2 parts per million. However, using the "bleach method" when my CYA is at 40 (which is where I keep mine) the recommended Target FC level is 5-7 and should never drop below 3. So because my target is 5 to 7 - I normally target around 8 or 9 because I get FULL sun all day long from sun up to sun down.

All of the liner manufacturers said that this was WAY to high to keep chlorine levels in a vinyl pool and it absolutely 100% would lead to premature fading of the liner (something I have indeed experienced w my own liner using the bleach method) and possibly weakening of the material itself - shortening it's overall life span. They all agreed that to maximize the life of the actual print on the liner - you want to be at no more than 2-3 parts per million MAX on a daily basis.

I asked if buying a better(more expensive) liner would help prolong the fading process and they all said no. It would only get you a thicker liner.

Anyone care to comment on this?

I'm a bit confused because this is not what I have read on here. But - these are the guys that actually manufacture and sell the liners so you would think that they know what they are talking about.

 

[cfherrman]

The pool industry is clueless. 8 ppm clorine with 40 cya is way, way, less harsh then 2-3 with no cya. 8 ppm off hand is like .3 ppm with cya.

Something else went on with your liner

 

[dschribs]

The pool industry is clueless. 8 ppm clorine with 40 cya is way, way, less harsh then 2-3 with no cya. 8 ppm off hand is like .3 ppm with cya.

Something else went on with your liner

Would a pool that uses pucks EVER have zero CYA though? Do you think the liner guys are not taking CYA level into consideration?

 

[Texas Splash]

Would a pool that uses pucks EVER have zero CYA though?

Not unless it was day 1 of a brand new fill and the pucks hadn't had time to dissolve yet.

Do you think the liner guys are not taking CYA level into consideration?

Often times that is the case. Many manufactures, builders, installers, and pool maintenance techs simply do not understand the FC/CYA relationship and push old/outdated standards to customers. Only recently are we hearing some industry leaders acknowledging the FC/CYA relationship standards introduced by scientists in their field and affiliated with this forum (i.e. Richard Faulk, AKA ~ Chemgeek).

 

[duraleigh]

Some years ago, both Leebo and I, independant of one another, ran some homemade tests about chlorine fading vinyl.

The unscientific but revealing results were neither of us could force the liner sample to fade (up to 25 ppm and NO CYA in my case.....I can't remember what Leebo's numbers were).. Different liners, different everything but the same results.

Sorry that your liner faded but I would have a difficult time believing the chlorine was at fault.

All of the liner manufacturers said that this was WAY to high to keep chlorine levels in a vinyl pool and it absolutely 100% would lead to premature fading of the liner (something I have indeed experienced w my own liner using the bleach method) and possibly weakening of the material itself - shortening it's overall life span. They all agreed that to maximize the life of the actual print on the liner - you want to be at no more than 2-3 parts per million MAX on a daily basis.

I would expect them to say nothing less......certainly no fault of the vinyl or it's printing process could ever be to blame

 

[dschribs]

Some years ago, both Leebo and I, independant of one another, ran some homemade tests about chlorine fading vinyl.

The unscientific but revealing results were neither of us could force the liner sample to fade (up to 25 ppm and NO CYA in my case.....I can't remember what Leebo's numbers were).. Different liners, different everything but the same results.

Sorry that your liner faded but I would have a difficult time believing the chlorine was at fault.I would expect them to say nothing less......certainly no fault of the vinyl or it's printing process could ever be to blame

Thanks! On the tests - how long were the samples subjected to that degree of chlorine? High levels for a shorter time might be less damaging than higher than recommended (by the liner folks) for a longer period of time. After all, like a pair of jeans or the paint on your car - fading takes time...

 

[duraleigh]

I can't remember the dwell time but it seems like I may have left mine in for several days......I think leebo may have done longer but don't quote me.....I can't remember for sure.

Your faith in the liner manufacturers is admirable but not well grounded. Why would you expect them to say that it is a fault of the liner?

But - these are the guys that actually manufacture and sell the liners so you would think that they know what they are talking about.

You mean sort of like the experts in the Pool Store that dole out all of their falsehoods? They sell the stuff.....so wouldn't you think they would be the experts???



PS - if Pool School suggests 5-7 ppm, you shouldn't be at 8-9 ppm FC.

If you are trying to compensate for full sun, bump your CYA to 60-70 ppm and then run 7-9 FC.

 

[cfherrman]

A big trend in the pool industry is "outs"

Makes sense that high clorine would bleach a liner, clorine bleach's clothes after all, so there a warranty out.

Makes sense that a saltwater pool is corrosive, I mean the ocean is, warranty out!

Your pool is mottling, chemistry, out!

.......

 

[Leebo]

Full disclosure.....none of the test was “Scientific.” It was done as I thought it would be neat to see, NOT because I wanted to publish it somewhere.

I took a some waist new liner and cut it into two sections and added it to a mason jar with tap water about a year or two ago. I wanna say it was two years but my memory was removed from my skull once I had children, so let’s go a year ago. I then added some bleach and set into a dark storage room. It’s been there ever since.




The cloudiness on the one is from me using a dirty screwdriver to remove the sample when I took a photo. It also is some rust as the Chlorine left unwashed rusted parts of the cheap-o tool. The swirl you see in the one is a drop from the OTO test today showing the water still has a valid FC level even after all this time.

Clearly there is some fading BUT this is a very small amount concedering I’d estimate a FC level of 20ppm and no CYA for one to two years.

 

[PoolguyinCT]

Liners are colorfast to higher levels of chlorine, than you would presume. Its chlorine in the presence of low ph which compromises the “inks” & a liners plasticity.
UV is the third catalyst.

Incidentally not all inks & Liner sheet material is the same.

 

[Leebo]

Its chlorine in the presence of low ph which compromises the “inks” & a liners plasticity.

Time and time again users who are in the industry who aren’t afraid of a little chlorine say the same thing. It’s all about the pH levels......NOT chlorine.

 

[PoolguyinCT]

Time and time again users who are in the industry who aren’t afraid of a little chlorine say the same thing. It’s all about the pH levels......NOT chlorine.

I have no fear of chlorine, I consider it a Lynch pin of civilization.

Inks in the medium blue spectrum do not fair well with chlorine. It’s is a chemical limitation of the medium blue ink & pigment. They have been rarely used last 5 yrs or so.

Other pigments “color or patterns” may show minimal wear in either high chlorine or low ph or both though it’s acceptable lifetime.

Regardless of the pigment/pattern all sheet material will loose it’s pliability low PH, and may absorb water when high chlorine is coupled with low ph.

A blanket statement can’t be made, inks bring unique chemical reactions & sheet material are proprietary formulations.

 

[needsajet]

When you take the old liner out, cut two pieces, lay them side by side, and take a picture. Take piece number 1 from the most shaded side of the pool, and piece number 2 from the side that takes the strongest blast from the sun. I'd love to see the picture

Also, if you get another chance to talk to those liner sales guys, ask them: "So what can you tell me about the effect of cyanuric acid on the liners?" I'll bet you a brick of beer they say, either: "What's that? Never heard of sayonara acid" or "Oh, you use stabilizer? That's part of your fading problem right there."

I strongly agree about "outs" and warranties. I just read a fridge manual that said... "the fridge requires 4" clear on each side and at the top, and 3" clear at the back." Does anyone here have 4" clear on each side of their fridge, and 3" at the back? Maybe in the garage, but these numbers used to be 1.25" to 2". Arghhh!

 

[PoolguyinCT]

When you take the old liner out, cut two pieces, lay them side by side, and take a picture. Take piece number 1 from the most shaded side of the pool, and piece number 2 from the side that takes the strongest blast from the sun. I'd love to see the picture [emoji4]

Also, if you get another chance to talk to those liner sales guys, ask them: "So what can you tell me about the effect of cyanuric acid on the liners?" I'll bet you a brick of beer they say, either: "What's that? Never heard of sayonara acid" or "Oh, you use stabilizer? That's part of your fading problem right there."

I strongly agree about "outs" and warranties. I just read a fridge manual that said... "the fridge requires 4" clear on each side and at the top, and 3" clear at the back." Does anyone here have 4" clear on each side of their fridge, and 3" at the back? Maybe in the garage, but these numbers used to be 1.25" to 2". Arghhh!

Their answer will be far from the above. It’s been communicated for years, cya is beneficial to a liners service life & function. First and foremost is a liner is waterproofing membrane.

Below from CGI tech bulletins: no matter who seams, sells or brands a North American liner, 4 out of 5 will be CGI sheets.

“... 3. Cyanuric acid stabilizer levels of 50 ppm were shown to reduce the magnitudes of weight and dimensional increases at both 6.0 and 8.0 pH. Therefore, cyanuric acid stabilizer appears to have
the ability to provide some insurance against the detrimental a ect of the unanticipated pH uctuation....” Incidents of wrinkling that have been reported to us, have almost always occurred in situations where cyanuric acid usage was deemed to be unnecessary, such as indoor/brominated pools. Therefore, it is recommended that all vinyl lined pools be routinely stabilized with
cyanuric acid, including indoor pools.

 

[needsajet]

Hey that's great backup for TFPC, and every bit of encouragement is helpful. Hopefully the experts manning the booths at trade shows get those bulletins.

 

[Swampwoman]

My liner made it to 15 years before starting to white out on the floor in the deep end. When I replaced it the year before last I read around a bit about the medium blue dye problem (the pigment they used to use has been banned).

In the hopes of getting good long life out of this new one, I went with a mottled pattern that also had black, white, gray, lighter blue, beige etc. My thinking was that hopefully that the way it fades when it ultimately does the effect will just increase the turquoise shades. I'll report back in ten years whether that strategy worked or not

This is the pattern I chose - Reef by lantham/Kafko. They brought it back last year (after I'd had to import it from Canada, go figure.)

I went border less...the middle shot is in my pool, the last shot is close up of the pattern during installation.

 

[JoyfulNoise]

You should have labeled one of the jars ... “Abbey Normal”

 

[PoolguyinCT]

You should have labeled one of the jars ... “Abbey Normal”

I’m old enough to get that joke...

 

[PoolguyinCT]

I’m compelled to add, liners that have only seen biguanide sanitizers, are amazingly supple and feel nearly new when being replaced, when the material removed from a chlorine pool is brittle.
& I’m comparing well cared for pools to each other, not 20k gallons of neglect and vinegar.
So there is definitely chlorine impact on the sheet material & it’s plastizers.
Though pigments seem to weather at similar rates..

But if anybody can deal with the nuisance ,frustration or temper tantrums caused by biguanide system they have more patience than I.