Stains on replastered pool

[curlytop09]

Hello,

My pool was re-plastered in early March. The pool builders took care of pool for first two weeks with daily brushing and chemical additions. After handing back over to me, I have brushed at least twice a week and kept chemicals balanced. Below is the latest test results

pH = 7.5 ( I add 2 cups acid daily to keep pH at 7.5 )
FC = 3.5
TA = 60
CH = 250
CyA = 30

I've noticed a light light brown-yellowish stain appearing on the walls. I have not noticed this on the floors. Most of the staining is in the shallow end of the pool.

I have checked water daily for FC and pH since handed back over to me and my chlorine levels have never been below 2.5 ppm. My pH will increase over the day but doesn't go above 7.8 before adding acid. I'll add baking soda on occasion as the TA starts to drift down. And I do use the BBB method.

I thought I was being a good pool owner by keeping water balanced and walls and floor brushed but I still have some type of staining. I tried to take pictures but camera would not pick up the stain. Any suggestions on what I can do to see what is causing the staining and how to fix.

Thanks

 

[JasonLion]

Try placing a vitamin c tablet on one of the stained areas and see if the stain clears up in that spot.

 

[Richard320]

Do what Jason suggests.

I'm suspecting iron staining. The builder most likely added a sequestrant during the fill, and it's started to break down with age. Are you filling from a well? Is the tap water high in iron?

Check out the picture in this thread. http://www.troublefreepool.com/threads/75755-Yellow-Stains

 

[curlytop09]

Wow, just tried the Vitamin C tablet and it came off with ease. I'm just happily surprised at how easy it will come off. But what is downside...will this be a long term problem? Anything I can do to prevent?

I'm sure this has been discussed on site, so I can search but what is most efficient way to handle for large areas. Right now I can probably manage with just tablets since mostly in shallow end. Not sure how to treat if much larger surfaces or if ends up in deep end.

We filled with city water but I'm not sure of iron content. What is considered high iron? Is this a test the pool store can do on a sample of my pool water.

Thanks for the quick tip. I was really getting nervous about messing up the new plaster job.

 

[Richard320]

http://www.troublefreepool.com/content/137-metals-in-the-water-and-metal-stains

 

[curlytop09]

Whew. Lots of info in that thread. We have company visiting next weekend and I'm almost afraid to try anything until after. See any issue with holding off a week?