Struggling to remove existing pool rust-like stains made much worse after wrought iron fence repair - pics attached

Rockstead

Well-known member
Sep 2, 2010
476
Montreal, QC, Canada
Pool Size
100000
Surface
Vinyl
Chlorine
Salt Water Generator
I can’t get rid of rust coloured stain, I’ve always had some on my stairs and now it’s spread around light fixture, bottom of walls near shallow end, skimmer, and other spots.

What made it get much worse was shortly after I had a welder perform some work on my wrought iron Pool fence.

I dumped in pounds of Vitamin C type product after lowering my Chlorine and PH to the recommended levels and it made no difference at all.

When my pool guy was winterizing my pool last year, he tried unsuccessfully to remove any of it, he lowered water on my stairs and applied some Muriatic Acid and the pool stair area that didn’t have a stain became really nice and white but it had no effect on the stain, he applied vitamin c product directly to the stain and nothing, pool guy more or less said that I’m on my own and it’s worthless because the kids at the store are unable to help.

I’ve attached some pictures from last year, I’m about to open my pool and was looking for any input before I balance, like if there are other things I can try now before adding chemical, so frustrating.
 

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Those really look like iron stains to me. The splattering on the stairs look like welder fragments, the rust around the light fixture, and others just seem like iron. Your location is blank. Are you on a well? You mentioned dumping in pounds of Vitamin C, but did you actually do an AA treatment like noted below? At any time di you happen to take a Vitamin C tablet and place it directly on one of those stains? I would try that too.


It's important to know the source of the iron as well if possible. The light fixture rusting is probably one now, but there may be others. But that article above will help.
 
Those really look like iron stains to me. The splattering on the stairs look like welder fragments, the rust around the light fixture, and others just seem like iron. Your location is blank. Are you on a well? You mentioned dumping in pounds of Vitamin C, but did you actually do an AA treatment like noted below? At any time di you happen to take a Vitamin C tablet and place it directly on one of those stains? I would try that too.


It's important to know the source of the iron as well if possible. The light fixture rusting is probably one now, but there may be others. But that article above will help.

No well water here.

I had placed AA right on my stains on the steps, and nada.

I’m assuming the source was from whatever came off the fence as the welder was working on it.

I don’t know what to do next, I’m happy to throw money at it but not sure how if AA didn’t work and Muriatic Acid didn’t work.
 
So the spots on the stairs are new right? Have you tried some dry acid if you have any? Put in a thin sock or nylon. If that works, your spots are copper. Also remember a pool can have multiple source stains at once (iron, copper, organic) just to make your day brighter. :) But if you find no results from Vitamin C (iron), dry acid (copper), or tabs/pucks (organic), then that's odd for sure. Magic Jack's sells an ID stain kit, but I'm not so sure it will tell you more. But might be an option.
 
So the spots on the stairs are new right? Have you tried some dry acid if you have any? Put in a thin sock or nylon. If that works, your spots are copper. Also remember a pool can have multiple source stains at once (iron, copper, organic) just to make your day brighter. :) But if you find no results from Vitamin C (iron), dry acid (copper), or tabs/pucks (organic), then that's odd for sure. Magic Jack's sells an ID stain kit, but I'm not so sure it will tell you more. But might be an option.

I always had these orange non removable stains on the stairs, you can feel them with your finger but nothing will remove it, the spots grew significantly after the residue from the welding work.

I mentioned that my guy had applied some Muriatic Acid and it didn’t budge the stain, wouldn’t that be the same as dry acid?

Am I correct in not trying to open the pool until I take another stab at this?
 
Dry acid has a different impact on copper whereas MA will fizzle on calcium. If you are going to try another AA treatment, now is the time before the water gets warm and chances of algae increase. I would hate to see you chasing your tail though. It would be good to know what those stains are from first.

Are your stairs fiberglass? If so, I wonder if that's some cobalt staining? I have a feeling though you have stains from multiple sources across the pool which complicates treatment a bit.

A couple things I probably should've asked right off the bat:
- Have you added any other chemicals to the water other than acid and salt? Oh - speaking of salt, what kind do you use? Some salts have mineral contaminants in them and can leave stains on the floor.
- Post a full set of test results. It would help to see your numbers.
 
I used tons of this stuff last year without any improvement at all, followed instructions on label.
Dry acid has a different impact on copper whereas MA will fizzle on calcium. If you are going to try another AA treatment, now is the time before the water gets warm and chances of algae increase. I would hate to see you chasing your tail though. It would be good to know what those stains are from first.

Are your stairs fiberglass? If so, I wonder if that's some cobalt staining? I have a feeling though you have stains from multiple sources across the pool which complicates treatment a bit.

A couple things I probably should've asked right off the bat:
- Have you added any other chemicals to the water other than acid and salt? Oh - speaking of salt, what kind do you use? Some salts have mineral contaminants in them and can leave stains on the floor.
- Post a full set of test results. It would help to see your numbers.

I’m not sure what my stairs are made from, they are pretty standard around here, everyone has those white stairs for inground pools.
I had not opened the pool yet, I’m in Canada and where I live we have a cold wiclimate and the pool gets winterized, are you recommended I start the motor and balance get the pool going, balance all the chemicals first?
I had not opened the pool yet, I’m in Canada and where I live we have a cold wiclimate and the pool gets winterized, are you recommended I start the motor and balance get the pool going, balance all the chemicals first?

I found a picture from the two different products I used last year, if it gives you any indication of what I should try next.

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I wouldn't try to do any AA treatment until you are ready to open and get the water moving. Now is a perfect time to do a little more research to try and ID those stains at the steps, liner, and light. Also something I though of .... fertilizer. Any of that been spread in the area? Those can leave awkward pellet-stains on the surface. What about salt around the pool to melt the ice?

@JamesW, can you think of anything else the OP should consider?
 
I wouldn't try to do any AA treatment until you are ready to open and get the water moving. Now is a perfect time to do a little more research to try and ID those stains at the steps, liner, and light. Also something I though of .... fertilizer. Any of that been spread in the area? Those can leave awkward pellet-stains on the surface. What about salt around the pool to melt the ice?

@JamesW, can you think of anything else the OP should consider?

Thanks, I appreciate your effort.
Unlikely to be fertilizer, I don’t use salt to melt Ice around the pool.

In terms of the salt I put in the pool, whatever is on sale, typically Windsor or Sifto brand.
 
I suspect that the welder used a grinder or cut metal with a cutting wheel.

This creates tiny iron particles that can be very difficult to remove once they bond to a surface.
 

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I suspect that the welder used a grinder or cut metal with a cutting wheel.

This creates tiny iron particles that can be very difficult to remove once they bond to a surface.

What do you recommend I do to try to remedy the situation? Like I said, I don’t mind throwing money at it, I’m fine trying different things at my expense, but so far nothing is even making a dent.
 
If ascorbic acid isn't working, I don't know what else would.

I suspect that the damage might not come off.

Did you see the image of the product I used, for ingredients it shows Citric Acid, with 2nd ingredient of Sodium Bisulfate, placing a few pounds of that directly in the pool and on the stairs did nothing, would it be worth buying a different product?
 
Try a nylon Scotch-Brite on the steps.

The light rust is probably bleed through from the galvanized steel wall. That's not going away until you replace the liner, treat the metal and reseal the faceplate.

The dark on the liner might be copper or some sort of contamination below the liner.

If it's contamination below the liner, it's not going away until you replace the liner.

If it's copper, it might come off with sulfamic acid, but that will convert fc to cc for a few months.
 
@JamesW
Wouldn’t my meulon pool brush be stronger than the Nylon Scotch Brite?

I put a lot of muscle with my current nylon brush and it doesn’t do anything.
My skimmer basket has the same stain, I’m wondering if I can test different solutions by trying to remover the color from the basket in a smaller environment, like a bucket. If I can get whatever it is to come off the basket in the bucket then I should be able to get it to come off the pool.

You mentioned Sulfamic Acid, can that be purchased at the pool or hardware store and what ratio am I mixing it at?

anything else worth re-trying using this method?
 
If you use something too abrasive, it will damage the step surface.

The problem is that when you get tiny iron particles, they can bond with most surfaces in a way that is very difficult to remove.

You can try sulfamic acid. It's sold as Jack's #2 copper and scale stuff.

I don't think that it's going to do that much, but you can try it if you want.

Note that your chlorine will get converted into CC for months.
 
@JamesW

Just to revisit this, I went to the pool store to have my water tested for metals and the results showed I don’t have any copper or iron, I don’t know if that’s a bad or good thing at this point.

I bought some PH- to put in a sock to try again and I bought about 4.5 pounds of Citrix Acid as well, I’ll try them on my skimmer isolated in a bucket As it has that same brown stuff all over it.
 
By any chance could this issue in any way be related to not using any Calcium Hardness? Could it be corrosion?

I’ve always followed the recommendation here that CH is a pool store money grab for vinyl pools.
 

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