Potentially dumb question about black algae

[rlsnights]

Do the black spots (all very small spots in our pool) just disappear when the algae has been killed or does it stain the white plaster making it hard to know if it's really gone?

Patricia

15,000 IG White Plaster Jet Vac Sweep Cart Filter new pumps
FC 75 (got a little carried away with the bleach while waiting for my test kit)
pH 7.2
TA 100
CH 280
CYA 50

 

[Guest]

Black algae grows into the plaster and can sometimes leave a permenant discoloration that requires acid washing to remove. However, if you catch it and treat it you can usually prevent thisd from happening. Black algae is slow to start and you REALLY have to ignore a pool for it to cause staining.

 

[rlsnights]

Thanks. Hopefully we've caught it early and will be able to get rid of it short of an acid wash.

Patricia