This spring I will finally conquer this stain

JamesW

TFP Expert
Mar 2, 2011
24,117
I can get a picture later today, but there was at one point an ionizer. It was broken when I moved in, so I removed it. This stain has been in the pool as long as I have been here.
Then I am sure that the stains are metals including copper and probably silver.

Just to clarify, it was an ionizer and not an ozonator, right?
 

heyyou488

Member
May 25, 2020
22
Pflugerville, TX
Then I am sure that the stains are metals including copper and probably silver.

Just to clarify, it was an ionizer and not an ozonator, right?
Ohh good question. I actually think ozonator. It was a long bar on top of my pool controller. It did not pump water through it so I am thinking Ozonator now that you said it?
 

heyyou488

Member
May 25, 2020
22
Pflugerville, TX
That is not used for metal staining. Re read the responses above.
I thought that was zero alkalinity? Also, if I use my spot thing with a cup of muriatic acid and leave it on the stain for several minutes it disappears and does not return. See pictures where there are spots without a stain. Those are from leaving a chlorine puck on the stain for like 24 hours or leaving the muriatic acid on the spot for 10-15 minutes. Scrubbing with either does not work. Only prolonged contact.
 

JamesW

TFP Expert
Mar 2, 2011
24,117
For zero alkalinity, I would take the system offline and just brush the pool to mix everything in.

Zero alkalinity is corrosive to metal and plaster.

You can remove the light and any ladders or rails.

I would minimize the amount of time that the water is at zero alkalinity. It will take off part of the smooth finish like an acid wash, but much less aggressive than an acid wash.

If it doesn't work in 24 hours, it probably won't work well.

If that doesn't work, sulfamic acid might work.

Note that zero alkalinity has risks that you need to consider before deciding what to do.

Taking the pH that low is very aggressive to everything and there might be unanticipated damage.

Consult a local professional expert and do your own research before deciding what to do.

Do at your own risk.
 

JamesW

TFP Expert
Mar 2, 2011
24,117
mineral-pure-pool-chlorine-r-40-64_600.jpg


This is an ionizer. It has a control box that sends power to a set of copper/silver bars in a tube attached to the pipe.

The tube has two terminals where the low voltage wires connect.
 

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JamesW

TFP Expert
Mar 2, 2011
24,117
Ok. I still think that it's probably copper and silver. Probably from algaecide.

For zero alkalinity, you can pull the lights up on the deck on their cords.

The light niches might be metal.

In general, zero alkalinity is an aggressive and risky treatment that should only be considered when necessary.

Don't do it unless you're really sure that it's worth the potential risks.
 
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JamesW

TFP Expert
Mar 2, 2011
24,117
 
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JamesW

TFP Expert
Mar 2, 2011
24,117
Also note that even if the treatment works, the metals will now be in the water instead of the plaster.

Most metals in the water eventually become stains.

If it works, the pool might look good for a year or it might begin to restain in a week or two.

You can add sequestrant and carefully manage the chemistry to reduce the rate of restaining, but it will probably come back to some degree at some point.
 
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heyyou488

Member
May 25, 2020
22
Pflugerville, TX
Ok. I still think that it's probably copper and silver. Probably from algaecide.

For zero alkalinity, you can pull the lights up on the deck on their cords.

The light niches might be metal.

In general, zero alkalinity is an aggressive and risky treatment that should only be considered when necessary.

Don't do it unless you're really sure that it's worth the potential risks.
I am happy to attempt a stain remover option if you think that is worth it before I go all Dante's Peak and turn my pool into a boat eating lake of acid. Do you think something like Jack's Magic is a better attempt first?
 

JamesW

TFP Expert
Mar 2, 2011
24,117
Jack's copper and scale stuff is sulfamic acid. It might work.

Note that it will convert the fc to cc for months.

You just have to use the tc as fc and ignore the cc.

Fc is free chlorine.
Cc is combined chlorine.
Tc is total chlorine.
 
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heyyou488

Member
May 25, 2020
22
Pflugerville, TX
Jack's copper and scale stuff is sulfamic acid. It might work.

Note that it will convert the fc to cc for months.

You just have to use the tc as fc and ignore the cc.

Fc is free chlorine.
Cc is combined chlorine.
Tc is total chlorine.
That settles it. I will try that this week before committing to something harmful like zero alkilinity.
 
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JamesW

TFP Expert
Mar 2, 2011
24,117
Ok. I am probably over emphasizing the risk of zero alkalinity to be safe.

Low pH can work, but the big question is if it will remove the stains without damaging anything else.

The lower the pH goes, the better and faster it will work but the risks also go up as well.

If I was to do the zero alkalinity, I would go right to zero TA and not lower.

I would probably only wait 8 hours before deciding to bail out if it wasn't helping.

I would also watch any metal carefully and bail out if it looked like it was changing color.

Some light niches are copper.

Copper will go from a dull brown to a bright shiny copper color like a new penny when it begins to be etched by low pH.

In any case, hopefully, the sulfamic acid will work and you won't need to try the low pH.
 
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YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
16,027
Evans, Georgia
Have you ever taken a water sample to a pool store and asked them to check for metals??

A note for when you get the pool back in line - You list your FC in your original post as running between 2.5-3.5ppm for a CYA of 50. That is entirely too low as the minimum FC for 50 CYA is 4ppm FC. Ideally you want to run 6-8ppm FC so it allows you to lose normal daily amounts of FC to the sun, and swimmers, and still have more than the minimal amount of FC.

Maddie :flower:
 

borjis

LifeTime Supporter
Aug 19, 2014
3,388
Pacific NW
Ya the only good free test from a pool shop is for metals. The test kits for that are spendy. $ 70 was the cheapest I found for the LaMotte.

I think the Jack's magic will steer you in a good direction. Anything else is guessing. Imo.
 

heyyou488

Member
May 25, 2020
22
Pflugerville, TX
Sorry for the long delay. I had to order the stain ID kit since there were not any locally and then get the chemistry right.

So here is where we stand:

I elevated the chlorine to about 40ppm and then let it naturally lower over the course of 2 weeks. This lightened the stains, but did not get rid of them just made them lighter. Once I got the kit and got the chemistry right in the pool. I did the tests with a sock and applying to the stains. None of the tests caused a dramatic change but"treatment #4" did lighten the stain slightly and Treatment #2 changed the color slightly. This seems to fit as treatment #4 is #2 and #1 layered on a stain. However, this is about $400 in chemicals for something that I am not positive will work because my test kit did not leave it completely stain free just changed the stain some. I have heard this is common on older stains.

Do you think I should try treatment #4 even at that price?
 

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