Algae and Black Worms

[Henry121083]

Hi All, Curious if anyone has ever has black worms in their pool "burn" into the floors of their (gunite) pool? Pic is attached, tried brushing and it doesn't come out, doesn't come out with vacuum either.

Also it seems like some light algae is not coming up with brushing or vacuuming either....Is it a water balance problem? How can I get rid of it?

Thanks in advance

 

[IceShadow]

What are your test results and what kit used to obtain them? You could just have some organic staining and some extra FC might take care of it.

 

[Xephyr]

Hi All, Curious if anyone has ever has black worms in their pool "burn" into the floors of their (gunite) pool? Pic is attached, tried brushing and it doesn't come out, doesn't come out with vacuum either.

Also it seems like some light algae is not coming up with brushing or vacuuming either....Is it a water balance problem? How can I get rid of it?

Thanks in advance

That looks like a ring left by a dropped tablet left there on the bottom. The high acidity from the chlor tablets ate through the concrete part of the plaster and probably just left the aggregate exposed. I have two of them in mine because I dropped 2 tablets into the pool in the winter by accident and the water was too deep and too cold to retrieve it.

The issue you will have is since the aggregate is exposed, the surface is really rough and attract algae growth, sometimes even under the exposed aggregate.

I plan to drain my pool over the winter, pressure wash, then polish necessary spots and refill in the spring.