Black Algae?

[jariv]

I noticed some black spots around the tile grout in my pool and was wondering if it’s black algae or not. Tried scraping with a toothpick and not really slimey. Just breaks off like I’m chipping away grout. Won’t come off with chlorine tab or extensive brushing. Just when I scrape with a toothpick. Let me know what you all think…
Fc=3

TC=3

Ph=7.7

Alk=120

CH=360

CYA=40

 

[Texas Splash]

While you don't seem to meet teh smudge criteria, it does look like BA to me. How old is this pool? Have you seen our BA page below?

Black Algae

This guide provides a step by step procedure for eliminating black algae in your concrete or gunite pool. Read full post here.

www.troublefreepool.com

 

[jariv]

While you don't seem to meet teh smudge criteria, it does look like BA to me. How old is this pool? Have you seen our BA page below?

Black Algae

This guide provides a step by step procedure for eliminating black algae in your concrete or gunite pool. Read full post here.

www.troublefreepool.com

Pool is fairly old. Pool was put in I think around 2005? I did check the link out and I’m thinking maybe copper stains from refilling water in the pool?