Yellow stain that won't brush off

[pfitz4]

I have a new yellowish-green stain in the bottom corner of my deep end. The stain appeared overnight. I added a bag of salt in this area of the pool yesterday. I noticed it this morning and thought it looked like algae, but it did not brush off at all. It is within a 3-4 foot area...imagine a glass of tea spilled onto the liner floor but more yellow than brown. Could this be related to adding the salt? I have never seen anything like this before (I tried to take a photo but I can't capture it with the light reflecting off the pool surface). Any ideas what caused this and how to treat it?

FC 9
CYA 60
pH 7.8
TA 70
CH 80
Salt 3200
Temp 70

 

[Texas Splash]

Could this be related to adding the salt?

Very possible. Some salt products have some metals in them (iron). I would try rubbing some Vitamin C tablets on the area to see if it confirms iron.

 

[pfitz4]

That's unfortunate, but I agree it does look like an iron stain. I used the same good brand of salt I always have. Probably won't brave the cold water just yet to try the Vitamin C test! I'll go ahead and research iron stain removal.

 

[Texas Splash]

You can try placing some Vitamin C tabs (crushed) in a thin sock or nylon, then tie to the end of a pole to save you a chilly dip. If it's just that localized area where the salt sat, you might get away with treating just that area later. We can give you tips.

 

[pfitz4]

You can try placing some Vitamin C tabs (crushed) in a thin sock or nylon, then tie to the end of a pole to save you a chilly dip. If it's just that localized area where the salt sat, you might get away with treating just that area later. We can give you tips.

I confirmed it is an iron stain. It was Clorox brand salt, and another poster said that brand has been known to have iron contaminants. I wonder why it just happened with this bag, when I've been using this brand for years.

Next time, should I brush the salt around to dissolve faster? Or would that make the stain appear on a larger area?

The stain is only in that corner of the pool where I dumped the salt. Any tips for spot-treating the area would be very helpful.

 

[Texas Splash]

Next time, should I brush the salt around to dissolve faster?

Yeah. you might have just gotten unlucky with one bag. I generally move the salt around every few minutes just so it's not sitting in one spot for a long time. Next time you might consider solar salt as it's usually very pure.

 

[pfitz4]

Thanks, I will do that. And I will stay away from Clorox brand.

I read on the forums about using a dish wand to apply the ascorbic acid directly to the stain. Will crushed vitamin c tablets work just as well? Thinking that would be easier to find.

 

[Texas Splash]

Will crushed vitamin c tablets work just as well?

Absolutely!