Rust stains on pebble tec

[Jmerich]

We bought a house that came with a pool in March. In the deep end mostly, there were several rust-like spots on the bottom, BB size. Today I noticed one on the side of the pool, about a foot from the surface, so I'm ruling out actual things left in the pool to rust.

My questions, any idea what this is?
Should I try Vitamin C?

From what I understand, pebble tec is about 6 years old.

I tried taking pics, but will not turn out clear.

 

[jblizzle]

It could be some rebar in the gunite happens to be close to the surface and resulting in the rust.

Vitamin C should lighten/remove the stain, but if it is due to rebar and not something that was sitting in the pool, the stain will reappear.

 

[JasonLion]

Try a vitamin C tablet on a small stained area and see how it goes. If that works well, it is worth considering the full AA treatment.

Most commonly stains that are easily removed with vitamin C are caused by iron in the water. If vitamin C does not remove it there are several other possibilities.

 

[Jmerich]

To try the Vit C test, how many tabs should I put in a sock?

Thanks...

 

[jblizzle]

Does not really matter ... enough to cover the stain you are trying to lighten. May work better if you crush them up.

 

[JasonLion]

One tablet held against the stain for 30 seconds is plenty for the initial test. For a treatment you will want quite a bit more.