Liner fading from FC?

Jump to latest Follow Reply
T

Tie Twist

0
LifeTime Supporter
Jun 5, 2012
45
Bolton Ontario Canada
Pool Size
80000
Surface
Vinyl
Chlorine
Liquid Chlorine
New liner installed last spring, CYA kept at 30, FC at 3 - 5, with two shocks performed over the summer (12 FC or so).

Liner at closing was slightly faded at and below water line, all the way around pool/

Liner supplier as expected, thinks normal FC of 4-5 is crazy high and the cause of fading. 12 at any time is crazy.

What are your thoughts on cause?
 
Re: Will FC levels of 6-8 fade liner? Pool store experience...

The FC levels shouldn't be the culprit of the fading. Your well with in the FC range for a CYA of 30. The shock level of 12 or a bit higher shouldn't hurt it either.
What color is your liner and how many mil thickness is it ? It may be just poor quality in the liner itself.
I keep my CYA at 40 and target an FC level of 7. My liner is 3 years old with no fading at all.
 
Re: Will FC levels of 6-8 fade liner? Pool store experience...

Pool water kept within the guidelines at TFP will have no affect on a good liner. My liner is nine y/o with no fading whatsoever.
 
Re: Will FC levels of 6-8 fade liner? Pool store experience...

30 Gauge Vinyl Liner. Liner is manufactured by Latham. Blue mini tile design. (like a three tone blue coloured tile pattern) pretty common / standard pattern.
Thanks guys, for your input.

Mike
 
As noted here medium blue is the color most susceptible to fading since it is produced from organic pigments. It's not the FC level that is relevant to the fading of organic pigments, but rather the active chlorine level which is proportional to the FC/CYA ratio. The colors that don't fade at all are generally made from inorganic pigments. This same phenomenon occurs with colored plaster as noted in this article.

If you have an extra piece of the vinyl, you could put it partway in pure unchlorinated water to distinguish fading between leeching associated with poor manufacturing of the vinyl material (i.e. chemical combinations not strongly bonded to each other) and bleaching from active chlorine. Leeching is similar to what occurs with fabrics that are not color-fast and fade with continued exposure to water (i.e. washing).

If you wanted to operate the pool with a lower FC/CYA ratio that is below what would prevent green and black algae growth (i.e. the TFP recommendations), then you may need to supplement with other products to inhibit such algae growth.
 
Thanks guys. My liner installer is a good guy. But as you might expect, he, and I am guessing the manufacturer as well, considers 12 FC (my shock level at 35-40 CYA) to be insane. This is what I would anticipate to hear from all these guys. I am sure any literature / guidelines they give me will refer to 1.5 FC levels. I also already had the "be careful what you read online" speach when I reference info from here. So I have this problem of credibility and who's credentials matter. I am sure I have maintained my pool to the TFP guidelines, however what liner manufacturer believes these are correct? I am 100% positive I will be told that 12FC is way too high at any time and that is the cause. I doubt a link to TFP will convince anyone either. I guess I will find out in the spring when they come to look.

I think I will put a sample in plain water in the meantime, good suggestion.

Intuitively, I have to say it "feels" like this is chlorince related, even though I know you will tell me about 100's of people using TFP / BBB method that have no issues.

My installer, who I think is trust-worthy, claims this manufacturer to be the best in the market, and that he has not had any fading issues yet (for the past 5 years).

Before you ask, I check my FC daily / every other day at least, my PH 2-3 times a week, and my CYA as needed, 3-4 times per summer. I am pretty anal about it too.

I have 30-40 CYA, target 3-5 FC and my PH is always within range, has never been lower than 7.2, since I have owned the pool.

Thanks.
 
Anyone ever checked the fc level that the granular shock adds. Just wondering if the pool store or liner manufacturer says add x number of bags of shock per week, what does that equate to? I would bet it's above 12, but that's just a guess. My only pool advice comes from here, so I don't know what they recommend.


Sent from my iPhone using Tapatalk
 
That's a good question, I was wondering the exact thing and was going to reference that point in my email to the installer guy. But like you, since I have no idea what that adds, I wasn't sure if it was a valid point.
 
Is it trichlor or dichlor that they usually recommend? 4lbs of trichlor would take my 34k gallons from 3 to like 17 fc according to poolmath. Dichlor takes almost 3x as much to do the same. That's where my original question came from. I don't know how much of which they recommend.


Sent from my iPhone using Tapatalk
 

Enjoying this content?

Support TFP with a donation.

Give Support
If you didn't notice this fading right after your shock, then it's more likely due to the average chlorine level and UV exposure over the extended period of time.

These instructions for that shock product of 65% Cal-Hypo are for 1 pound per 10,000 gallons which would be an increase of 7.7 ppm FC so with their recommended 1-1.5 ppm FC between shocks the FC would be at 8.7 to 9.2 ppm FC so just under 10 ppm FC. This product is 73% Cal-Hypo and recommends using 9-18 ounces per 10,000 gallons which would be 4.9 to 9.8 ppm FC increase. This product is 57.8% Cal-Hypo with recommended dosage for shock of 1 pound per 10,000 gallons and double that for superchlorination or algae killing so that is 6.9 to 13.7 ppm FC. This product is 29% lithium hypochlorite with recommended dosage every other week of 1 pound per 6000 gallons which would be 7 ppm FC. This product is 99% Dichlor with recommended dosage of 1 pound per 10,000 gallons (depending on what you read in the description) which is 6.6 ppm FC.

So overall the "shock" is in the range of 6-14 ppm FC so in the ballpark of 10 ppm FC.
 
I didn't notice any fading until I drained water to winterize, so unfortunately I can't say one way or another on that one.

I doubt it is UV related, as it is all the way around, and I don't get full sun either (only half day of direct sun). Also the liner is suppose to have UV protection nowadays, built in to it according to installer.
 
OK then. It sounds like it might be "normal" vinyl liner fading for that color that uses organic pigments. Personally, I would say that's something they should have warned you about so that you could have chosen a color that used inorganic pigments that wouldn't fade. If you want to minimize fading from chlorine oxidation, then you'd have to keep as low an active chlorine level as you can get away with. The shock levels weren't for very long so effectively just added 10 days of normal exposure for every day at shock level. So it's really your normal chlorine level that is more relevant since that's for a far longer period of time.

As for the rarity of people on this forum having issues with vinyl liner fading, many may have colors that use inorganic pigments and it may be that those with a similar color to yours have an organic pigment that is either more resistant to reaction with chlorine or is less likely to leech from the vinyl or was otherwise manufactured in a way that is better to last longer.

The only way you'll be able to have a lower FC/CYA ratio than what we recommend to prevent algae growth is to supplement with some other type of algae prevention. This falls into two types that don't have serious side effects (like staining from copper ions, though that's less risky in vinyl pools). One is using Polyquat 60 weekly. The other is using a phosphate remover to get phosphates <= 100 ppb. Either way, you could probably drop your FC/CYA target to half what we recommend so roughly 3-4% so roughly 1 ppm FC with 30 ppm CYA or 1.5-2 ppm FC with 50 ppm CYA. You'd still see fading, but at roughly half the rate -- assuming all the fading is from the chlorine level.

Your separate jar test would help determine how much fading is from the chlorine vs. how much is just from being in water (i.e. leeching). This is a long-term test so to keep the water from evaporating you can cover the jar (so some vinyl is in the water and some is above it). You'd occasionally open and stir its contents or you could get a magnetic stirrer if you have a device that can occasionally stir the water. If you find fading of the vinyl below the waterline just from long-term exposure to un-chlorinated water, then that is certainly something you could show your liner installer and liner manufacturer.
 
Be sure to report back with whatever you find out (if you do any experiment). That's how we learn new things and apply the chemistry to the real world.

If you wanted to accelerate the jar testing, you could use hot water. Higher temperatures will accelerate whatever is going on. Not sure how you'd keep it hot unless you had a hot plate you could adjust to have hot but not boiling water. Then again, the vinyl installer and manufacturer would likely say that hot water wasn't a fair test, but they'd be wrong. It's how most accelerated testing for chemical processes are done. The only issue is getting so hot that certain secondary reactions occur that would not have been seen at lower temperatures at all, but that shouldn't happen for the temperature I'm talking about with vinyl (such as 120-130ºF). That temp should accelerate things by roughly a factor of 8 compared to pool temp. So one month of testing would be like 8 months in the pool.
 
Was ust at a meeting with Latham about liners. One of the product line leads mentioned that due to EPA regs liner pigments weren't lasting as long as they used to since all the good chemicals have had to be reduced or removed. We notice on light colored liners that fade appears faster than with darker liners. Liners printed on white seem to fade fastest. Had one customer that liner faded in less than three years. They test water daily.
 
ewkearns said:
Can you folks give guidelines as to how to choose a liner color? How does one know whether a liner has organic pigment or not? When does a manufacturer "print on white?" Who makes the most face resistant liners?
Click to expand...

All good questions. I want answers too. I know mine is printed on white. It has a scroll on tile like border with the main portion being a water reflective look. Mostly medium blue with swirls of light white throughout. I have the piece that was cutout for the steps. It looks mostly the same after six years except where the previous non tfp owners dumped granular chlorine in it to open and close it and apparently didn't brush it around. Also screwed my ladder up pretty good with the granular chlorine.


Sent from my iPhone using Tapatalk
 
My liner is approaching 14 years from what I can gather from previous owner, and while it has faded quite a lot, the design seems to help conceal that fact ;)

For this reason, when I HAVE to get a new liner, i will get the same pattern -- it's sort of tie-dye, which conceals oh so many problems...at least from a distance! You really only notice that its lighter when you look at original swatches...

Its Latham's "Royal Prism" and this is a link to what the design looks lie in a full pool for those interested in a very forgiving pattern: (the age is about seams, but shows how the liner actually looks...just google Latham royal prism to see a swatch up close) https://lathampool.com/ultra-seam/
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply