Calcium hypochlorite immediately stained plaster black/purple

[allan1622]

I sprinkled some product on the areas with black algae with the intention of letting it sit for 5 min before scrubbing it with a metal brush. It immediately discolored the plaster. I’m normally meticulous with testing before adding anything, but I dropped the ball big time here.

I’m screwed right?

 

[allan1622]

 

[JamesW]

Probably copper.

Put a vitamin C tablet on a spot or maybe try ALUM.

 

[JamesW]

I sprinkled some product on the areas with black algae with the intention of letting it sit for 5 min before scrubbing it with a metal brush.

Why do you think it was black algae?

Is there copper in the water?

 

[JamesW]

Copper in Pool Water - Further Reading

www.troublefreepool.com

 

[JamesW]

Calcium hypochlorite immediately stained plaster black/purple​

Purple is usually copper cyanurate.

What is the CYA level?

 

[allan1622]

Probably copper.

Put a vitamin C tablet on a spot or maybe try ALUM.

There wasn’t any Alum in stock, so I just grabbed what was available (ascorbic acid / Vit C).

Seemed to help, but unsure why the top step isn't clearing out.

Should I brush? Or just let the filter circulate

 

[JamesW]

Copper stains can be difficult.

Can you post a full set of tests?

 

[JamesW]

Put a vitamin C tablet on a spot or maybe try ALUM.

Note that I said "Spot" to diagnose the problem before going to a full treatment.

 

[allan1622]

Copper stains can be difficult.

Can you post a full set of tests?

Note that I said "Spot" to diagnose the problem before going to a full treatment.

Sorry, I’ve been in full blown panic mode and overlooked that. Yes, I’ll test now and update you.