Pinkish tint on my concrete what is this?

Manju Vista

New member
May 16, 2025
3
Austin Texas
I am a new pool owner. We had algae that I treated with very high levels of chlorine and now I have a pink tint that I am not able to brush off or get rid off even with aggressive scrubbing. I’m seeing it along steps at where the algae was. Help! How can I get rid of it? Pool guys are recommending an acid wash but I worry that will damage the pool concrete. Cya40 ph 7.8 chlorine 8
 

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Welcome to TFP.

Yes, acid washing will remove layers of your plaster and reduce its life.

How old is your plaster?

That looks like very mild staining on old plaster. That is just the way plaster wears. View it as natural character.

If you try and get old plaster looking like new you will spend lots of money and effort in a frustrating effort.
 
so i didnt see this stain alll over the pool, it was a very clear light blue all over. the problem i see now is that the pinkish stain is all over where the algae was. could it be an alge that was not mustard algae? when we brougnt the house is jan it was not this pinkish color but the cya was sky high so it took me several weeks to lower that and get it within range. now the whole pool where aglae was has this stain. i can try vitamin c, i need to research that part. also manganase. thank you for your suggestions. not sure how old the plaster is.
 
What is the CYA level?

Copper Cyanurate is a purple color, so high CYA can combine with high copper to produce a red or purple color.

when we brougnt the house is jan it was not this pinkish color but the cya was sky high so it took me several weeks to lower that and get it within range.
High CYA can create copper cyanurate if you have used any products that contain copper like algaecide.