Hi, we obtained brown staining on liner after putting in metal remover and a couple bags of shock. It seems the staining was exactly where the bags of shock were dumped along the edges. Trying citric acid to remove. Need help in how to use it. Will this through other levels off ? What do I need to be aware of. I was thinking of dumping in over stain with filter off and letting sit for a while then scrubbing ? Anyone have insights or experience with this ?
Using citric acid to remove stains
- Thread starter Jennifer8
- Start date
- Jun 22, 2014
- 51,990
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
That could depend on how much citric acid you plan an adding. How much staining are you talking about? Care to share some pics?
My question would be about this brown staining. Are you sure it's iron? Are you on a well or has your water supply been known to have a high iron content? I would be curious to know if you might have copper in the water? Your signature is blank so we don't know if you have a heater or anything. Do you typically use copper-based products, algaecides, or items called "Blue" something?
Not to bad but around the outside of pool my husband is using his hands and taking it under and throwing it On it it’s working !!
Attachments
- Jun 22, 2014
- 51,990
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Great! Keep an eye on your FC level at some point to make sure it doesn't drop too low. Glad to hear it's working.
- May 23, 2015
- 25,674
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Ascorbic acid is the correct chemical to use. But since you’ve gone ahead and used it, the citric acid will work, albeit with some caveats. It can create some nasty chlorinated organic compounds with chlorine and it takes more chlorine to neutralize it than an equivalent amount of ascorbic acid. It will also drop the pH more strongly than ascorbic acid. You may notice elevated CCs for a while depending on the reactions that occur.
Next time use ascorbic acid.
Next time use ascorbic acid.
My FC is super high and we’re fighting that it’s coming down now !! So this will help with that thanks !
sktn77a
Gold Supporter
Hi chlorine levels can oxidize lesser metal stains to a more difficult stain to remove (ferrous to ferric, cuprous to cupric, etc).
I’ve read copper stains need citric acid and that’s what I had on hand I will try and find ascorbic acid next time if needed.
So tested today with strips , still waiting for my Taylor kit to come in mail. FC is reading white or 0 on test strips only have shock or chlorine tabs on hand.
- May 23, 2015
- 25,674
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Hopefully you haven't read that on TFP because it's simply not true. Neither citric acid nor ascorbic acid works on copper. Copper stains can only be lifted using sulfamic acid and the process is a royal PITA because sulfamate causes false high CC readings for weeks after it is used. Typically we advise people with heavy copper staining to use sulfamic acid to lift the stains and then drain and refill the pool to get rid of the copper metal. Sequestering agents will only hold the copper metal in solution until they breakdown from chlorine exposure (similar to how iron is sequestered) and then the stains will come back. Filtration doesn't remove copper from the water. So, at the end of the day, if a pool owner does not get significant rain dilution (remove pool water and let rain refill the pool), manual draining and refilling is the only way to get rid of dissolved copper ions.
Interesting. I could not find anything helpful on the site. I followed a few older forums but links were not active any longer. I read it else where. It worked and stains are removed. Now my FC is 0 (testing strips; waiting for Taylor kit in mail) only have chlorine pucks and shock and not sure how much to use. We have been fighting super high FC recently. Now we’re at 0 everything else looks good any recommendations?
- May 23, 2015
- 25,674
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Your zero FC is because of the citric acid. On a molar basis, it requires 3 times as much chlorine to neutralize citric acid as opposed to ascorbic acid which is 1:1 on a molar basis. So you are simply fighting the chlorine demand from adding the citric acid. You have to keep adding chlorine until the FC starts to hold.
How did you determine these were copper stains? Did you use an ID kit or just simply test with other chemicals? Have you been adding copper containing products to your pool?
Ok thank you good to know! So chlorinated shock would be good to stay with and a few pucks?
We used a diy heater using copper coils. From store reading high copper levels. We put in that metal remover they suggested . Then husband shocked the pool. Staining happened around outside of pool where he poured in the shock.
We used a diy heater using copper coils. From store reading high copper levels. We put in that metal remover they suggested . Then husband shocked the pool. Staining happened around outside of pool where he poured in the shock.
- May 23, 2015
- 25,674
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Liquid chlorine is all you should be adding to your pool at this time until you can get a proper test kit of your own. Shocks and pucks are only going to lead to other problems. Please review the Pool School on this forum to understand the TFPC Method better. You can not mix and match advice you get here with the pool store or online in other forums. It won’t work and it will just lead to confusion and lots of pointless discussions about “why does that online site say this but you guys say that??” I’m not trying to be short with you, but just honest. You either follow TFP or you don’t. There’s no half measures.
Also, your homemade copper heater is clearly causing you problems … I suggest you stop using it.
Also, your homemade copper heater is clearly causing you problems … I suggest you stop using it.
- May 23, 2015
- 25,674
- Pool Size
- 16000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Just raise your FC slowly. Maybe just add a few ppm at a time and then let it circulate and retest. If you raise FC too quickly the stains will come back.
Ok thanks for that advice according to the pool math app I should add 3-81oz bottles of bleach which I am about to add
Citric acid works differently than ascorbic acid.
Ascorbic acid is a reducing agent.
Ascorbic acid can sometimes work on copper, but it can sometime have no effect or it can make the stains worse.
Citric acid is not a reducing agent, it complexes with the copper to form copper citrate.
Citric acid will reduce copper, but only at elevated temperatures.
Sulfamic acid also complexes with copper
Copper complexes with the sulfamic acid to form copper sulfamate.
Ascorbic acid is a reducing agent.
Ascorbic acid can sometimes work on copper, but it can sometime have no effect or it can make the stains worse.
Citric acid is not a reducing agent, it complexes with the copper to form copper citrate.
Citric acid will reduce copper, but only at elevated temperatures.
Sulfamic acid also complexes with copper
Copper complexes with the sulfamic acid to form copper sulfamate.
Super Fast Removal of Iron & Copper Stains with Citric Acid Spray!
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