Any Guesses - What is This

[dpdeleon]

Hi everyone,
See attached photo. I'm embarrassed to say that this has been in my pool all summer season. Because its in the deep end where my drains are I figured perhaps if I keep the water balanced all season it would go away on its own but it didn't - now I'm in attack mode.

I'm thinking its black algae but I don't have this anywhere else in my pool. Not sure what to do. I'm going to the pool store today to get a brush that can do a better job (wire brush) and although I'm concerned about a wire brush on gunnite (concrete) I'm more concerned with letting whatever it is stay in the pool.

Whatever this is it is only around my drains and nowhere else in the pool. Any guesses? Any suggestions?

Thanks,
denis

 

[Chasarms]

Have you tried vacuuming it up?

 

[Texas Splash]

It looks like it could be Black Algae. You should dive down there and try to scrape some of it off with your fingernail and swipe onto a white paper towel. If it is BA, it will require an elevated SLAM level coupled with some consistent brushing to break-up the algae spores of the BA and allow the chlorine to penetrate the plaster as much as possible. Also see the following link for more details.

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

 

[ajw22]

Is your main drain operational and drawing water?

If there is stagnant water under the covers algae may be growing there. I would want to have the drain covers removed to check under them. It looks like whatever is growing under the drain cover and showing on the edges.