Is this a copper stain?

[scchan1w]

Just had my pool replastered and it's been filled 4 days ago. I didn't add any sequestering agent as I though my fill water was low in minerals (and hence metal). But I'm noticing some light green stains showing up. I don't think it's algae as the water temperature is probably mid 50s - I didn't add chlorine until day 3, but FC was around 0.5 to 1.0 in my fill water. I raised FC to 3 to 4 yesterday and I think the stains are lighter now, but they don't brush off. I have GLB Sequa-Sol, wondering if I should add it now. Should have maybe added it during the fill but wasn't sure if it would do more harm than good. Thanks for any suggestions.

 

[mknauss]

Try Vitamin C. A couple tabs in a sock and set on it.

Could there me a metal fleck that got there? I assume you did not abalone.

 

[scchan1w]

There are more than one such spots, some bigger but lighter. So it’s probably not a piece of metal that fell in.

thanks for the vitamin c suggestion. I will try it but wondering if I should add the sequestrant

 

[mknauss]

You might still try the Vitamin C trick. Just to see if it is iron or not.

Copper stains do not present themselves like that. And it would have taken a lot of copper (such as running very acidic water through a heater for a long time) to get enough copper in your pool right after a replaster.

 

[ajw22]

Sequestrant keeps metals in solution. They will not help you once the metal has been deposited as stain on the surface.

I doubt that metals in water will get deposited on the pool surface in 4 days.

 

[scchan1w]

Thank you @mknauss and @ajw22. I will monitor it and try Vitamin C when I get a chance. Good to know it's most likely not metals. I didn't see any new spots and the existing ones are the same or slightly lighter (e.g not getting worse)