Trying to rid my plaster pool of a large amount of staining

[lwoods941]

Hello,
I need help. I have tried a few things to rid my plaster pool of a large amount of staining. I most recently tried the vitamin C test and saw the stain was lifted where the tablet was so I tried the ascorbic acid. After adding the ascorbic acid, the stains remain the same. I have attached photos of the stains. Any suggestions?

Thanks

 

[JasonLion]

Ascorbic acid will not remove all stains, only some of them. Did you try holding a vitamin C tablet against the stains for 30 seconds before doing the ascorbic acid treatment? And did it affect the stains?

 

[lwoods941]

I placed the vitamin C tablets on the steps where there are stains. It removed the stains as the tablets disolved, but not immediately

 

[Guest]

Have you ever used a copper based algaecide, do you have a heater, or do you know if there are metals in your water?
THe stains look like either manganese or copper. Ascorbic acid should work on manganese but not necessarily on copper. It would also be helpful if you could post a full set of test results.

 

[lwoods941]

I will get results from a water test at my local pool company and post it later today. How can you tell if an algaecide is copper based..and is there any way to get rid of copper stains?

Thank you so very much!

 

[Guest]

How can you tell if an algaecide is copper based
It will list copper sulfate or chelated copper on the ingredients or it will be a "three month' algaecide or possibly a black algae killer or mustard killer (although other things besides copper are marketed as these kinds of algaecides also)



..and is there any way to get rid of copper stains?
Usually acid washing the pool. Sometimes copper stains can be treated in the pool but the procedure can take weeks and the pool is closed during the treatment. Also, heaters need to be bypassed since the treatment lowers the pH of the water by quite a bit. It is, in effect, a no drain acid wash with strong reducing agents in the water.
Thank you so very much!

 

[lwoods941]

Hello again,

I got my water tested.

PH = 7.2
Calcium= 120
Alkalinity = 100
Chlorine = .5
Copper = .2
Iron = 0

The pool company suggests adding "Super Erace" again which I did in the past with no results. This will also take the copper out of the water. I do have a heater. I can't see an active ingredient in the "Super Erace" but it is made by the Phoenix company.

Thank you

 

[Guest]

I am going to guess you chlorinate with trichlor tabs and you have had more than one instance where your pH has 'crashed' and the pool was acidic. It is close to that now. I suspect this is the source of your copper. Sequesterant will deactivate the copper in the water but will not remove it. However, sequesterant breaks down and needs to be added as a weekly to monthly maintenance chemical when there are metals present.
You are probably going to have to acid wash to get rid of the stains. I suggest you click on the pool school link in the uppper right corner of the page and start learning how to care for your pool properly.

Why did you NOT get a test result for CYA? Why is your CH so low with a plaster pool?
You really need to take control of your pool. It's not hard as everyone on here can attest to.

 

[lwoods941]

My pool is not usually this out of control. I lowered the chlorine because I just put in the ascorbic acid which lowered the PH.

 

[frustratedpoolmom]

Hello again,

I got my water tested.

PH = 7.2
Calcium= 120
Alkalinity = 100
Chlorine = .5
Copper = .2
Iron = 0

The pool company suggests adding "Super Erace" again which I did in the past with no results. This will also take the copper out of the water. I do have a heater. I can't see an active ingredient in the "Super Erace" but it is made by the Phoenix company.

Thank you

I wouldn't use it.... if it didn't work before, it likely won't work now.

Please see the article - Recommended Levels in Pool School. I would agree that an acid wash it probably your last option at this point, and once you do that, be sure to keep your levels in range for your pool - so get the CH level up to the recommended range and confirm your CYA level.

I would recommend you get your own test kit, there is an article in Pool School that compares them.

 

[jfinholm]

I have the same type of stains. We finally all concure that they are copper stains. My PB is acid washing on Monday.

It has been a very long, expensive, and frustrating trail! see my pics
no-stains-until-salt-was-added-t14936.html