Yellow stains on liner

Texas Splash

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As I understood the process, since I am not replacing the water, the iron never actually leaves the water, so my job is to keep it suspended in the water which would require monthly maintenance doses of the Metal Free, but it has not even been 3 weeks, and it is back. What did I do wrong
"28", you are correct. So after the AA was completed, the return of stains at such a low FC level must indicate your iron level is quite high in the water - and/or the pH got too high. Without exchanging water, you do your best to manipulate the iron by keeping the FC within limits, keeping the pH low (probably under 7.5) and using sequestrant. I do see a pH of about 7.6 recently. I would knock the pH down to about 7.2 for a couple days and see if that helps. Continue to keep good notes of your actions and test numbers. Each iron-pool is different, so owners get a feel for what levels and techniques work best for their water.
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
So how do I use that? Do I stuff it in my skimmer? How much do I use? How do I know when to replace it, and do I have to throw it away or wash it out and reuse?
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
I just watched a video on the "sock method", using 3 socks inside each other and attach to return jet, to filter out the iron. I am going to try that as well.
 

Texas Splash

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I just watched a video on the "sock method", using 3 socks inside each other and attach to return jet, to filter out the iron. I am going to try that as well.
Good luck to you. Be realistic about the process as well though. When the iron is well controlled and in solution, you may not collect as much iron as if it was actually precipitating-out like when it is trying to stain.
 

AndyTN

Bronze Supporter
Mar 27, 2019
210
Memphis
I put the Polyfill in a laundry bra bag which my wife wasn't using and I just let it sit in the skimmer. It has a zipper on it to keep the Polyfill contained and easy to change out every couple weeks. The CuLator packs will work as well for proactively absorbing metals if you don't mind paying a bit more for the convenience. There are threads on TFP like the one below with people going to the extreme to filter out as much iron as possible.


Either way, you have to start removing iron from your pool or the stains will come back. I have used CuLator packs, Polyfill, and Metal Free for the past 4 years but the number one thing which made a huge difference for me was a water exchange immediately after AA treatment.
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
I put the Polyfill in a laundry bra bag which my wife wasn't using and I just let it sit in the skimmer. It has a zipper on it to keep the Polyfill contained and easy to change out every couple weeks. The CuLator packs will work as well for proactively absorbing metals if you don't mind paying a bit more for the convenience. There are threads on TFP like the one below with people going to the extreme to filter out as much iron as possible.


Either way, you have to start removing iron from your pool or the stains will come back. I have used CuLator packs, Polyfill, and Metal Free for the past 4 years but the number one thing which made a huge difference for me was a water exchange immediately after AA treatment.
So if I do a water exchange after the AA treatment, do you mean the entire AA process including the metal free, poly-60, etc. or just following the addition of AA?

I just added AA and stains gone afterless than 1/2 lb per 10k gal. I was thinking about running overnight then adding metal free. Is that ok or do need to add it now and run for 24 hrs.
 

AndyTN

Bronze Supporter
Mar 27, 2019
210
Memphis
After the AA lifted the stains, the iron is now released in the water so immediately doing the water exchange will pump out your "iron water". Fresh water coming in is going to dilute your iron so you will basically cut the iron PPM by at least half. Only add chemicals after pumping out "iron water" or else you will be pumping out your chemicals too.

Do you have a submersible pump? If you do, have that pumping water out of the shallow end while having your hose running water at the bottom of the deep end. Pool pump off during the water exchange. The colder fresh water will sit at the bottom.

If you only have your pool pump to set to waste pumping from your main drain, then you have two options. To exchange roughly 50% of the water, just simply pump out enough water until there is a foot of water left in the shallow end and then simply refill. To exchange more than 50%, drain water level down a foot and then have a hose running full blast in the shallow end. Use plastic sheeting or a tarp to slow down the mixing of the water and then turn off your pool pump when you get to one foot a water left in the shallow end. Your pool pump will be able to pump out water faster than your hose can fill up.

You can add the polyquat anytime after you stop pumping water out and you can start adding a small amount of chlorine to start killing off the AA. If you are going to use polyfill, I would not use the metal sequestrant until after you have run the water through the polyfill for several days. Either way, you should still bring up your FC and ph slowly over a week. You will need to eventually replace your cya and baking soda.
 

AndyTN

Bronze Supporter
Mar 27, 2019
210
Memphis
Also, don't get discouraged if you start seeing some minor staining reappear in a month or two or even next Spring. As I mentioned, I have done the AA treatment with water exchange each year for the past 3 years due to minor stains coming back. The previous owners of our house set me up for failure. Our pool looked like the first picture when we bought the house and the 2nd picture when we moved in 2 months later. Even with a brand new liner, stains came back a little since iron can precipitate on the surfaces of your pipes and inside your sand filter. Make sure you bypass your filter when doing AA treatment.

1588927554157.png 1588927679149.png
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
I am a bit puzzled. I added the AA, then after stains gone, I added Metal Free last night around 10 PM. It is now 6 PM, so metal free has been in for 20 hours. Water is totally clear, and my pH and TA are the same as they were before I started pH 7.4, TA 50. I thought that this AA treatment was supposed to lower them both. I was planning to buy some poly-fill tomorrow, and stuff it in a pillow case, and put in Skimmer just to see what happens. I have had a culator pack in for 3 days, and it has not changed a bit - still white, and not even puffy or anything. Also, I tried the 3 layered sock on one return jet, and after 2 days, there was very little brown staining.
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
Update. After metal free in pool for about 36 hours, water is crystal clear. Added 1 qt poly-60 just to make sure I don’t get algae. Water turned very cloudy after about 30 min.

I got some poly fill and stuffed in skimmer basket, also stuffed some in a small cotton bag and put on top of basket. After 4 hours the poly fill is still white but the bag has a bunch of brown stuff on it.

My test results are: FC 0, TA 60, pH 7.2, CYA 40

should I start to bring FC up slowly now? If so what should my target FC be w

also, I tested my hose water since I am considering a 1/3 water exchange and it is FC 2, pH 8.2, TA 30
 

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Texas Splash

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Maybe some iron residue in the pic. Little hard for me to tell. Scary not having any FC right? So if you are at the point where you are satisfied with the results of the AA treatment, it's time to transition. You'll continue to use a good sequestrant while slowly increasing the pH and TA with Washing Soda. Best to review the Ascorbic Acid Treatment - Further Reading page for ste-by-step instructions. Best of luck!
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
While I really appreciate all the advice, I am getting really frustrated. This is the 2nd time in a month I have done the entire AA treatment, and after just 4 days of following it to the T, my metal stains are starting to appear again, which I confirmed by simply dropping a pinch of AA in the area. Following is a log of everything I did. There must be something I am missing. Please jump back into this thread and help me.

Thurs 7pm 1.5lbs AA, added CuLator pack to skimmer
Thurs 10pm 2qts Metal-Free (instructions say 1qt/20k gal, and my pool is 27k, so there was extra put in)
Sat 10am 1qt Poly-60, added poly-fill to skimmer
Sat 8pm FC 0, added 69oz bleach, pH 7.2, TA 60
Sat 2PM FC .5, added 48oz bleach
Sun 8am pH 7.4 - added 10oz Muriatic Acid, TA 40 - added 8lbs baking soda
Sun 10am FC 0 - added 60oz bleach, pH 7.2, TA 60
Sun 12pm FC 1.2, added 28oz bleach
Sun 3pm FC 0.6, added 48oz bleach
Sun 6pm FC 1.2, added 35oz bleach
Mon 8am FC 1.4, added 38oz bleach, pH 7.6, added 17oz Muriatic Acid

At this point I was really questioning my testing, so at 10 am Monday, I had water tested at pool store, and found pH 7.4, FC 1.0, TA 70, CYA 20, oh and since now they do metals with the computer, they found 0.1 iron, 0.2 copper, they also said my CC was .45 (I ran out of the reagent for this test and have not been testing for CC lately)

Apparently my CYA test was way off, so around 4:30 pm after work, I added 24oz Muriatic Acid, waited 4 hours, then added 1/2 gal liquid stabilizer, waited 4 hours and at 1AM added 48oz bleach.

This morning (Tues), my tests are FC 2.4, pH 7.2, TA 70, CYA 30, but I am going back to pool store for another CYA test, since they now do it computerized, so not as subjective.

I am confused as to why the staining is back, why my pH kept going up. Only thing I can think of is that my pH reagent was a couple years old, and past the exp date. But I bought a new one, and ran 2 tests comparing old to new, and did not see much difference. The only thing that was really off was the CYA assuming the pool store test was accurate. Any thoughts?
 

Texas Splash

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I am confused as to why the staining is back, why my pH kept going up.
PH typically tends to rise anyways unless the TA is extremely low. I can only summarize that even though the pool store is showing low levels of iron and copper, it may actually be higher. Either their testing is flawed a bit (which is normal) or skewed from the chlorine already added to the water. Sorry to hear you're still battling that thing. Iron in pool water is no joke. Aside from a water exchange, you appear to be meeting all the prerequisites of good water management by keeping the FC and pH low and using a sequestrant. Adding the CYA might help because when the CYA is low, the chlorine is more harsh which might make the iron react quicker.
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
Should I add more metal-free, or if the staining is already starting to show up, do I need to add more AA, and repeat the whole process? I am losing confidence in the whole AA treatment, if I cannot even keep the staining off surface for more than 4 days.

If I were planning to do a water exchange in 1/3 increments to keep water bill from exploding, should I do that first? Does it matter if my hose water is FC 2, pH 8.2, TA 30?
 

Texas Splash

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I think if you are going to do a water exchange to try and get on top of this thing, do it first. No sense is wasting chemicals. If your replacement water is iron-free (hopefully), that will help consider bally. But if at all possible, try to exchange as much as you can at once. Multiple exchanges will take longer to see the desired result Once staining occurs, sequestraunt might help if caught early, otherwise it will need a another AA treatment to remove it. Sequestrants are ideally designed to keep the iron in solution with the water before it can stain. Your hose water if 8.2 will certainly aggravate any iron, so pre-filtering is recommended, followed by careful adjustment of p once in the pool.
 
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cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
When you say more aggressive AA treatment, do you mean adding a lot more AA, than it would take to make the stains go away? I can get the stains gone with about 1/2 lb per 10k gal. First time I added 3.5lbs, 2nd time I added 1.5lbs. What exactly do you mean by more aggressive?

Also, I had pool store test hose water...

pH 7.8
FC 1.5
Iron 0.3
Copper 0.0

I am just trying to think of ways the metals are getting into the pool. I do not want to do a water exchange and be back in this spot again. The screws that hold my skimmer faceplate in have been getting rusty, could this be causing the metal infiltration? Is it possible that there is something in my sand filter that can be causing the metal? I have read where people found a screw in their sand. My sand is 9 yrs old, and I have always thought that it hasn't been filtering very well last couple years. I know sand is supposed to last a long time, but I was thinking of replacing mine.

Also, do you think cellulose fiber would help in my filter?
 

Texas Splash

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When you say more aggressive AA treatment,
Sorry, not more aggressive, just "another". :hammer: That pool test of 0.3 is troublesome for sure. 0.3 is the threshold for iron problems. If the source is already 0.3, you can imagine how quickly it is multiplying once added to the pool. I doubt the sand or finding one rusted screw is the issue. If that pool store iron test is close, that's your problem. Without a water exchange, the iron will multiply. If you can't have fresh water delivered and must refill form the same source, your best hope is to pre-filter the hose water through one or even multiple filter methods (i.e. polyfilled buckets) before it gets into the pool. Some owners go through some serious effort to fabricate pre-filtera. It's not perfect, but it can help.
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
Seems like these AA treatments are just a band-aid. It costs me $150-$200 each treatment, and I am at 2 so far. Would be great to figure out how the metal got there in first place before dropping another $200.

- 9th year with this pool, and never had metal staining until a few months ago.
- Atlanta has had a lot of rainfall this year.
- So you don't think it could be from rusting skimmer faceplate screws?
- You don't think it would have anything do with the 9 yr old sand in my filter?
- Regarding the iron in hose water - I almost never have to add water to pool. Maybe 1 time per year, so not likely coming from there.
- What about 2 stainless ladders that are non-removable since they have been in the holes for so long?
- I have called 2 water delivery services, and in both cases, they get the water from the county supply and do not test it or provide any info on what is in it. Also, the prices are ridiculous - $500 per 7200 gal. which would be $2,000 for my pool!
 

cholmes28

Well-known member
Jun 9, 2014
179
Marietta, GA
I just read that liquid chlorine gets its yellowish color from iron. I have been using the wal-mart liquid chlorine and the HDX liquid chlorine for the past 2 seasons. Before that, I only used Kroger brand bleach. I switched because the Kroger bleach lowered from 8.25% to 6%, and kept the price the same, so it got pretty pricey. Has anyone ever tested the liquid chlorine for metals before?
 

JamesW

TFP Expert
Mar 2, 2011
18,448
Iron or other metals degrade sodium hypochlorite. Good quality manufacturers avoid iron as much as possible.

The yellow is not from iron.

Chlorine is yellow.
 
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