Stained plaster

[RESISTENCIA13]

Hello all!

So when I opened my pool in May 1, I noticed organic stains from acorns trees in my neighbor's yard and treated using The OS Spot Stain remover and Muriatic Acid (works great! See attached pictures). However, as I treated the stains spot, I started to notice that those spots now looks whiter than the rest of the pool plaster (see attached pictures, which shows my plaster with no stains. However, the picture does not show the whiter acid treated spots). I have two theories as follows:

Theory 1: When my pool was built 2 years ago, the pavers dust got to the water in slightly stains my plaster to a level I could not notice until the acid removed the organic stain and the paver dust stains.

Theory 2: The stains was is normal aging stains and the acid is making the treated spot brighter/whiter.

Regardless of what happened. Now I have clearly visible whiter/brighter spots (where stain were treated). Is there anything I can do to restore the whiter/righter plaster of my pool to match the stained treated spot?

 

[duraleigh]

That looks like calcium scale. Is it a bit rough to the touch?

 

[RESISTENCIA13]

I have not got into the pool yet, but the spa does have plaster rough to the touch.....I though it was the undissolved salt as my CSI is within limits -0.16. MY CH is 525 PPM

 

[pooldv]

The fact that acid works on it also supports that it is calcium scale, it wouldn't work on organic stains, chlorine would. With CH at 525 if your PH spends some time at 8.0 or above scale can develop. More here, Pool School - Calcium Scaling

 

[RESISTENCIA13]

Thanks for the reply and info.

The fact that acid works on it also supports that it is calcium scale, it wouldn't work on organic stains, chlorine would. With CH at 525 if your PH spends some time at 8.0 or above scale can develop. More here, Pool School - Calcium Scaling

 

[RESISTENCIA13]

Guys,

I need some more help. I drained my pool and will be acid washing tomorrow morning. I notice some streak, but not sure if is damage to plaster or normal plaster uneven coloring. I recalled seeing streak similar to this one when the pool was built before filling it, but want to confirm so if I need to do anything else I can do tomorrow with the pool drained. Attached are the pictures.