White marks on vinyl liner around/above water line

[bbillingsley1985]

Wanted to see if you guys have any advice on what this is, if it can be fixed, and how to prevent further damage.

We are now entering our 4th year with this pool and vinyl liner. I noticed about midway through last year a few white marks along the waterline on the liner. I'll attach pics below. This year, I've noticed it a little more. It's only happening mainly on one corner of the pool. That corner does have the most wind flow and probably ends up seeing the sun the longest. The cosmetic part is a concern, but I'm mainly worried about it potentially getting worse and actually cutting through the liner. On my 3rd picture, I actually tried rubbing the white spot with my finger and instantly it sort of moved the white stain and filled in more area/made it worse (you can see it in the more circular area)

Any ideas on what the heck this is? It isn't anywhere but the waterline and maybe even slightly above the water line? Nowhere else but there. We do get heavy winds that would occasionally blow any organics floating on the top of the pool over in that area (but it isn't much) and that also probably ends up being the hottest area of the pool with the sun hitting it the longest. I have not tried to use anything other than just water to clean that area of the liner. Not sure if anything would help.

I've been very good with keeping pool clean (use a robot daily) and balancing/chemicals. Pool has been at the optimal levels 100% of the time during the last 2 seasons. For reference, current data (using the TF-Pro with new reagents this year)
FC 6.0
Salt 3000
PH 7.5
TA 60
CH 125
CYA 60

I don't believe I have any mineral issues. Tests were good about 2-3 years ago on all minerals (that one was a pool store ran one though) and I know for a fact I've put in no minerals (copper, etc.) since that time and about half the pool ends up drained each season with rain etc. We have normal city water (not well water).

Appreciate any help on what this is.

 

[setsailsoon]

Wanted to see if you guys have any advice on what this is, if it can be fixed, and how to prevent further damage.

We are now entering our 4th year with this pool and vinyl liner. I noticed about midway through last year a few white marks along the waterline on the liner. I'll attach pics below. This year, I've noticed it a little more. It's only happening mainly on one corner of the pool. That corner does have the most wind flow and probably ends up seeing the sun the longest. The cosmetic part is a concern, but I'm mainly worried about it potentially getting worse and actually cutting through the liner. On my 3rd picture, I actually tried rubbing the white spot with my finger and instantly it sort of moved the white stain and filled in more area/made it worse (you can see it in the more circular area)

Any ideas on what the heck this is? It isn't anywhere but the waterline and maybe even slightly above the water line? Nowhere else but there. We do get heavy winds that would occasionally blow any organics floating on the top of the pool over in that area (but it isn't much) and that also probably ends up being the hottest area of the pool with the sun hitting it the longest. I have not tried to use anything other than just water to clean that area of the liner. Not sure if anything would help.

I've been very good with keeping pool clean (use a robot daily) and balancing/chemicals. Pool has been at the optimal levels 100% of the time during the last 2 seasons. For reference, current data (using the TF-Pro with new reagents this year)
FC 6.0
Salt 3000
PH 7.5
TA 60
CH 125
CYA 60

I don't believe I have any mineral issues. Tests were good about 2-3 years ago on all minerals (that one was a pool store ran one though) and I know for a fact I've put in no minerals (copper, etc.) since that time and about half the pool ends up drained each season with rain etc. We have normal city water (not well water).

Appreciate any help on what this is.

If anything, your CSI is too negative and it looks to me the deposits are making an arc that's more like wheel marks from a cleaner or something. Do you have a robot or cleaning service? Can you scrape some off or is the coating on the liner scratched?

 

[bbillingsley1985]

If anything, your CSI is too negative and it looks to me the deposits are making an arc that's more like wheel marks from a cleaner or something. Do you have a robot or cleaning service? Can you scrape some off or is the coating on the liner scratched?

I do have a robot that's used daily. I used to have the Hayward Aquavac 650 which I loved. At the end of the season last year, it was replaced under warranty with a Hayward Tigershark QC (which I don't love near as much). The marks would of started during the previous robot but I will say it skims the entire water line of the pool and no other areas except that one area in the corner has any issues.

After I smeared it by trying to clean somewhat hard with my fingernail I gave up on trying to scrape anything until I posted here. It does appear with my finger that there is an indentation where the marks are.

 

[setsailsoon]

I do have a robot that's used daily. I used to have the Hayward Aquavac 650 which I loved. At the end of the season last year, it was replaced under warranty with a Hayward Tigershark QC (which I don't love near as much). The marks would of started during the previous robot but I will say it skims the entire water line of the pool and no other areas except that one area in the corner has any issues.

After I smeared it by trying to clean somewhat hard with my fingernail I gave up on trying to scrape anything until I posted here. It does appear with my finger that there is an indentation where the marks are.

Yeah, I'm afraid something may have gotten to your liner coating. Let's see if we can get an expert that knows more than I do about liners to help @Texas Splash @ajw22 @kimkats can you help or point this lady in the right direction? Thank you!

 

[bbillingsley1985]

Yeah, I'm afraid something may have gotten to your liner coating. Let's see if we can get an expert that knows more than I do about liners to help @Texas Splash @ajw22 @kimkats can you help or point this lady in the right direction? Thank you!

Thanks for the help. One quick thing I'll add is these photos are zoomed in which makes it look a bit worse than it actually is, but its definitely very noticeable. I'll attach a few more pictures zoomed out a bit more. These were taken in the dark though so not near as good.

 

[Texas Splash]

Yikes. Sure seems like something has been brushing-up against it in that corner. Do you use a cover?

 

[bbillingsley1985]

About half the time during off season (about October 15 to March 15) we do use a pool cover. It's the standard mesh cover and we have spots drilled around the pool to tie the cover in.

Man I'm starting to wonder if it is that new stupid robot. On the pictures from my original post, the first 2 are the pictures from that corner (to the right of the steps). The 3rd picture with the blotchy spot I smeared is to the left of the stairs though and not in a corner. Those are the only 2 spots where I have any issues. I will say in that corner, from day 1, that liner is not flush to the wall above the water line. In other words, I can feel a gap when I push it against the wall with my hand. It's similar in the other corners but that corner is the worst. Now I'm starting to wonder if it is the robot slamming into that area as it tries to clean waterline.

My CSI appears to be about -0.8. I never cared about CSI being a vinyl pool but is that something I should mess with? I never have to touch Ph or Alk throughout the year. Looks like adding calcium or raising PH/Alk could change that but I'm very hesitant to mess with any of that when all I've had to do is basically add cya at beginning of season and then run the swg the last 2 years.

 

[Texas Splash]

A cleaner sure seems like a more plausible possibility.

 

[setsailsoon]

About half the time during off season (about October 15 to March 15) we do use a pool cover. It's the standard mesh cover and we have spots drilled around the pool to tie the cover in.

Man I'm starting to wonder if it is that new stupid robot. On the pictures from my original post, the first 2 are the pictures from that corner (to the right of the steps). The 3rd picture with the blotchy spot I smeared is to the left of the stairs though and not in a corner. Those are the only 2 spots where I have any issues. I will say in that corner, from day 1, that liner is not flush to the wall above the water line. In other words, I can feel a gap when I push it against the wall with my hand. It's similar in the other corners but that corner is the worst. Now I'm starting to wonder if it is the robot slamming into that area as it tries to clean waterline.

My CSI appears to be about -0.8. I never cared about CSI being a vinyl pool but is that something I should mess with? I never have to touch Ph or Alk throughout the year. Looks like adding calcium or raising PH/Alk could change that but I'm very hesitant to mess with any of that when all I've had to do is basically add cya at beginning of season and then run the swg the last 2 years.

I was only checking CSI when I thought it might be a deposit. If you just stay Within tfp recommended ranges you'll be fine. The problem is mechanical damage. Nothing to do with chemistry I don't think.

Chris

 

[bbillingsley1985]

Yea it has to be some external factor doing it and only thing that makes sense would be the robot. I'm now trying to brainstorm how to prevent it from happening and further damaging it in the future.

Any ideas on if they make some sort of vinyl repair deal or something that I could set over it to serve as an extra barrier? I actually have some pieces of the original vinyl from when they originally installed it. If hypothetically I have enough of the top design left to essentially paste the exact same design over the damage, is that something I could do? If so, how would I go about it?

 

[kimkats]

You sure can "patch" it. The main thing would be to "round" the corners of the patch. It sure is worth a try!