Can this be black algae?

[Yorkiegirl]

I have a 35,000 gallon inground SWG vinyl liner pool. Pool chemistry is in line. This afternoon the FC was 7.8 and the CC was zero. PH was 7.4. I use a Taylor 2006 test kit. This evening I noticed black in the crevice around my steps. I used a brush and it peeled out rubbery black strips. It was mainly in this area with a tiny amount around the skimmer. My chlorine levels are holding just fine. I’m not noticing any drop off. Could this possibly be black algae? If not, does anyone have any ideas what it could be?

 

[mknauss]

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

Smear it on a white sheet of paper. Black Algae will leave a green smear.

I do not think black algae would come off that easy.

 

[Yorkiegirl]

I tried to smear it earlier. It didn’t disintegrate enough to smear. It does seem to have a blue green tint to it in bright light. It’s sitting on the pool deck and I just looked at it. It dried into a hard much thinner “string”.

 

[JamesW]

It's not algae. It's probably gasket material.

 

[Yorkiegirl]

That’s what I originally thought. I don’t remember ever seeing black in the crevices around my steps though.

 

[JamesW]

It's probably been there the whole time.