what is your best advice to prevent liner fading?

[abfab]

I'm getting a new liner next week (obsidian/butterfly effect). Current liner is about 20 years old (original) and was almost completely faded when we bought the house 10 years ago. What little faint pattern there was has completed disappeared since then. This is my first ever liner replacement and I would like it to stay beautiful for as long as possible. From what I've read that Is that mainly a matter of keeping chems balanced? Is there one in particular that impacts fading?
Pool is in full sun, Canadian winters with safety cover and I follow TFP recommended chem levels. Installer said that because I have swg this liner may only last 10 years (about 12 for traditional chlorine pool) but given how well I did with this one could get a bit longer. True? New liner is 30 mil.

 

[UnderWaterVanya]

Curious as well. My situation is similar. We recently replaced our old liner which had behaved like this is described. Bleach pool until the new liner went in.

 

[IceShadow]

Two things to my understanding are a danger to your liner - low pH and excessive FC.

Watch the pH and make sure it doesn't drop too low. With a SWG there shouldn't be any acid except what you add (unless the rain is acidic), so just be careful not to go below 7.0 with the pH and you should be fine on that end.

For FC, keep an eye on what your pool has and keep it in ratio with the FC/CYA Levels. Ideally keep your FC at the higher end of the suggested range and never get close to minimum. That means higher FC levels than skirting the minimum but if you do get algae you'll need to follow the SLAM Process. This is a lot nicer on the liner than what other methodologies suggest (which is raising FC to an ungodly level to "shock" away the pool), but it's still higher than the standard suggested ranges, so it means more potential fading.

The nice thing about the TFP way is that you don't do a weekly "shock" to raise up the FC, which is what is the likeliest culprit with liner bleaching. Some bleaching is going to happen with the chemicals and UV exposure that pools have, but this should be the way that minimizes it the most.

 

[IceShadow]

Also, salt pools are chlorine pools. There's nothing inherently different about salt pools that would cause a liner to fade quicker, except that the FC is up where it should be pretty much all the time. If anything, you can typically keep your FC a bit lower compared to your CYA in a pool chlorinated in a SWCG than one with traditional chlorination via added liquid chlorine, so it should help keep the liner fresher.

 

[sls]

When I need to "shock" or run at a higher chlorine level, I always make sure the water level is at or below my normal water level. This helps keep the fading below the water which helps hide it some. You will start to notice the fading much more when you drop the water level during closing time each year.

 

[abfab]

Two things to my understanding are a danger to your liner - low pH and excessive FC.

Watch the pH and make sure it doesn't drop too low. With a SWG there shouldn't be any acid except what you add (unless the rain is acidic), so just be careful not to go below 7.0 with the pH and you should be fine on that end.

For FC, keep an eye on what your pool has and keep it in ratio with the FC/CYA Levels. Ideally keep your FC at the higher end of the suggested range and never get close to minimum. That means higher FC levels than skirting the minimum but if you do get algae you'll need to follow the SLAM Process. This is a lot nicer on the liner than what other methodologies suggest (which is raising FC to an ungodly level to "shock" away the pool), but it's still higher than the standard suggested ranges, so it means more potential fading.

The nice thing about the TFP way is that you don't do a weekly "shock" to raise up the FC, which is what is the likeliest culprit with liner bleaching. Some bleaching is going to happen with the chemicals and UV exposure that pools have, but this should be the way that minimizes it the most.

Can you expand upon the impact of SLAM on liner fading?
Does SLAMing prior to closing increase liner fading? I've read some posts that recommend SLAM then keeping Chlorine level higher than normal to avoid algae. Won't this elevated CH over the winter fade the liner? I usually close with chems balanced, then SLAM when I open it.

 

[IceShadow]

The FC level for a SLAM is designed to keep the FC relatively gentle on pool surfaces and equipment. If your FC is in ratio for your CYA level, then the HOCl is pretty safe. The result is that 12ppm of FC at 30ppm CYA is far less harsh on your liner and equipment than 3ppm FC at 0 CYA.

It's still elevated, and I have to think that the HOCl will still cause fading over a period of time, but the real danger is dumping in a ton of FC once a week well over recommended SLAM levels for your CYA like most people do with weekly "shocking".

 

[abfab]

The FC level for a SLAM is designed to keep the FC relatively gentle on pool surfaces and equipment. If your FC is in ratio for your CYA level, then the HOCl is pretty safe. The result is that 12ppm of FC at 30ppm CYA is far less harsh on your liner and equipment than 3ppm FC at 0 CYA.

It's still elevated, and I have to think that the HOCl will still cause fading over a period of time, but the real danger is dumping in a ton of FC once a week well over recommended SLAM levels for your CYA like most people do with weekly "shocking".

Thanks for explaining. Very helpful!