Brownish staining on pool liner?

I'm gonna double post! I wrote most of this up this morning for another post and I don't want to retype it.

I don't think you are going to be able to do just a localized cleaning and have the stains removed permanently .. the iron is in the water and you really need to deal with it at the level of the whole pool. The staining is the sign that tells you that there is Iron in the water at a high enough concentration to cause stains. So I think you should prepare yourself to treat the whole pool and here's why. Ascorbic Acid (vitamin C or AA as we refer to it around here) will remove the stains from the vinyl and other surfaces, but it only changes the iron to another form so it will go into the water. Eventually it will change its form back and restain unless the iron is removed from the water. (I'm really trying to not dredge up high school chemistry, its painful for some;)). You can

1) Use AA on the entire pool to remove stains from the surfaces then drain and refill with iron free water
2) Use AA to remove the stains and then use a sequestrant that will bind with the Iron in the water...eventually you will have do it again, because the sequestrants will break down and the iron is released. Some people do an AA treatment followed by the sequestrant followed by a drain and refill to be assured of getting it all.
3) Use AA and then use a sequestrant that can be filtered out.. and to my knowledge there is only one product that will do that called Metal Magic.
4) Get the iron to go into the green form (your water turns green) and then setup a polyfil filter to filter the Iron out.

Then afterward you need to figure out where the iron is coming from. If you are on a well its likely in your fill water and you can set up a filter for that, or I have seen owners set up cistern systems that allow them to use rain water to refill their pools.

Let me send you down these rabbit holes for your information on how these work.

Here is my recent-ongoing thread on treating Iron:

And another one:

The often referenced polyfill filter thread:
Thanks for the great info!

I have ordered some iron test strips to test the water. They arrived today, so I'll check it this afternoon to get an idea of how bad it is.
I had already ordered Robelle Mineral Out in large enough quantities to treat the pool (sequestrant) and it also arrived today. I didn't see this post until afterwards, so i'll do some research. It supposedly works the same as metal magic, but I cannot confirm that.
I have not yet ordered any citric or ascorbic acid, but i will get that coming before i do anything else.

I am on city water, so I don't think the iron is coming from there, but I plan to test it anyhow just to be safe. We had a LOT of rain this winter, so i am wondering if maybe that was the culprit. I can't think of anything else that would have caused it.
 
I have trace iron in my city water too. Most of them provide water quality test results. Mine indicated trace iron. I get that same light staining. It's iron, just enough to be a nuisance.

To get it to go green as mguzzy said, wait over next winter to let chlorine deplete. When you go to add the first chlorine, it will turn green .

I'm seriously considering a whole home 3stage iron remover to the pool spigot to nip this in the bud once and for all. So annoying.
 
I finally have everything on hand and plan to start the process to get rid of the staining tomorrow. Here's where I stand to date.

I have 5lbs of citric acid powder (was faster to get than ascorbic acid), 4 quarts of sequestrant, a big bag of polyfill, a 13 lb bag of baking soda, 4 boxes of Borax, granulated stabilizer, and about 12 gallons of 10% chlorine on hand. and some Polyquat 60. Right now the water is crystal clear.

Current test results as of 1 hr ago:

CYA - 30 (still low)
TA - 60
pH - 6.8
FC - 0

The pool has been brushed, hand vacuumed, and the robot is running now. Pump runs 24/7.


I'd like some input to make sure that what I am about to do is the correct procedure.

I'm going to follow the Ascorbic Acid treatment plan (assuming it will still work similarly using citric acid). I have tried to contact Robelle's Mineral Out customer service to confirm whether or not their product will allow filtering out the particles via polyfill, but have yet to get anyone to answer. (Update: They replied that yes, it will allow iron to be filtered out afterwards, similar to Metal Magic).

Once the staining is gone (and assuming that i can try to filter it out) I plan to adjust the CYA to ~50, then the pH back to 7.2, keep TA around 60, and finally bring the FC back up to ~6 ppm.

Does this sound like a solid plan?
 
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Did you refer to the AA treatment in the Wiki? it has something to say about using CA over AA. buried in the article is this:
So 1 pound of ascorbic acid is equivalent to 1.2 pounds of citric acid which is equivalent to 0.5 pounds of oxalic acid.

Also I don't think you will catch anything with the polyfill once you add the sequestrate. It will bind to the iron. In order for the poly fill to work the iron needs to be in "green form" . At least that was my experience when I used Metal Magic.

Sounds like a plan.. keep us posted!
 
Did you refer to the AA treatment in the Wiki? it has something to say about using CA over AA. buried in the article is this:


Also I don't think you will catch anything with the polyfill once you add the sequestrate. It will bind to the iron. In order for the poly fill to work the iron needs to be in "green form" . At least that was my experience when I used Metal Magic.

Sounds like a plan.. keep us posted!
Yep I factored in the difference since I had to go with CA. I didn't really understand what it took for the iron to reach "green form". I have it all here and I'm going to read up on it some more while waiting for the CA to do it's business.

Fingers crossed, the CA just went in!
 
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I did take a few before. I haven't taken after pics YET because of rain. I'll take some in the next few days and post the before and afters. I can say that after using the CA I didn't see a noticeable change that day. We were a bit bummed out after 4-5 hrs and I was prepping to just go buy Ascorbic acid and start over.

The next morning, the liner was completely blue with zero stains left! I even noticed that my pool light and stairs were bright white! They've never been this bright and the liner has never been this blue.

I immediately added the sequestrant and went ahead and stuck in the polyfill to the baskets just to be safe. Last night, the polyfill was pretty much a reddish-brown color so i swapped it with some fresh. This morning early I switched by MPV back to filter and added some baking soda into the pool to slowly start bringing the TA back into range. It was below 50ppm when I tested yesterday. I'm going to retest late this evening and continue on with balancing the water again.

I don't know if it will come back, but for now we're excited! Thanks for the knowledge!
 

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I can’t get out to take pics because of rain so here’s a before that I have and an after from my security camera. Hopefully that shows the difference. Cousin Eddie (yes, our robot has a name) has never really been this visible on the screen.
 

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