Faded liner

I am new to the bleach method, but thanks to all you people, so far, so good!

I now know that the higher your CYA, the higher you have to keep your free clorine. (something I had no clue about before). Of course every season, all season, I'd be using the pucks, which has sent my CYA sky high (100+). Also I was keeping the chlorine at about 3 PPM, which was OK according to the pool store. Not good.

Naturally (as you can imagine) I fight algae every year. I'd have to BLAST the pool with VERY high chlorine levels to kill it, but it would come back again because of the low FC I had been maintaining. Round and round I went, and now my poor vinyl liner is totally faded from the high shock levels I always had to do.

We are getting a new liner installed in a week or 2, so I didn't bother to drain and refil to lower the CYA. My fill water has a much lower CYA. I will test when the time comes to make sure the exact level, but it's around 30. I don't plan on using the pucks anymore.

When your CYA is high, you have to hold your FC high to compensate. In simple terms, the high CYA sort of "ties up" the FC. So am I correct in assuming that even tho the CYA affects your FC's ability to work, it does NOT affect how much the FC will fade the liner? The higher you keep your FC, the more chance it has to fade your liner, regardless of your CYA level? Am I correct?

I hope made sense with my question here. Thanks. :)

No - the CYA makes the chlorine less effective. Meaning that at a CYA of 100 with 25ppm is equivalent to NO CYA and 10ppm at shock levels. There is no higher chance of your liner fading at either point.

HOWEVER IMO - to be on the safe side I have seen it recommended that a liner pool remains below 20ppm. If your CYA level is higher and constitutes a higher than 20ppm shock level - it would be better to drain/refill to bring down the CYA level so that you do not need to shock to over 20ppm than to accidentally overdose the pool and have permanent damage to your liner.

When you shocked before - were you testing your own water - or was the pool store handing you 6 lbs of stuff and telling you to throw it in your pool? It could be that if you were not testing your water - that your shock level was a lot higher than needed and that is what faded your liner.

Your fill water will not have CYA in it. That is something that has to be added.

I was testing it myself Simmons. At one point this year, I had to add 14 bags of shock before I could get the level to hold overnight. My liner had already faded by then for the most part, so I didn't really care if I faded it more at that point. I just wanted to kill that algae. It came back again of course after that, because I didn't know I had to maintain my FC so high.

And you are correct Watermom. All I did to get a quick general idea of the fill water, was stick a test strip in the hose water. It registered the lightest CYA reading on the strip, but I assumed that was a level higher than 0. Now that I look closer, it is indeed 0.


Thanks much both of you.

Doggie, how are you?, I've seen a few of your posts today, but no direct contact - welcome to the forum:) As I understand it, and the more I learn here, the more sense it makes, chlorine can cause liner fading and failure, but low pH is the real killer. I'll assume that you don't have a heater (if you did the trichlor would have taken it as the first victim instaed of your liner). What tends to happen with the trichlor feeders is that, though you think the water is good, it's slowly adding cya and reducing the pH - without testing, or if you use a bad tester, you end up with chlorine that can't do it's job and an acid bath (the pH of pucks is ~2.5). Unfortunately I see the results a few times a year (when i have to go out and replace the heat exchanger on an 'unattended' trichlor pool).
You've done the BEST thing for your pool by comming here to learn the 'proper' way to care for it. If you follow the advice given here, you should encounter no problems with the new liner (and it'll last it's expected # of years, if not more).
As long as you don't have a SWCG, keeping the cya ~30 should do you fine, if you have lots-O-sun, you may want to bump it up a little more to retain the desired level of cl, and just stick to Ben's Best Guess chart for your chlorine needs.

Waste, you are right on there. I didn't bother to mention, that I've been buying PH increaser in FIFTY POUND BAGS!! So I really have had to work at it, but I've kept the PH up. And as you can imagine, my ALK is sky high as a result. Basically the pool is in need of help, but I'm simply waiting for the new liner, and a fresh fill in order to do it right this time. Let me add tho, that since I turned off the puck feeder I haven't had to add PH up one time! And the water is crystal clear!

Also, we do in fact have a heater, which works just fine. Maybe that's my small particle of luck in this whole messy situation. :)


Thanks for the welcome. I agree that finding this place was the BEST thing that I could have done.

Quote:

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Originally Posted by waste

chlorine can cause liner fading and failure, but low pH is the real killer.

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Right on Waste! Every pool I've seen with faded liners had high CYA but they also have, or had, very low PH. A friend’s pool has a 2' radius white patch that they assumed was from the bleach he used during a Mustard algae battle. I told him that it was more likely from leaving pucks in the skimmer while the pump was off. The high chlorine/low PH water would then settle down through the skimmer and up through the drain. :eek:

Dave