Possible Black Algae

  • Last Post 31 July 2019
tomintampa posted this 31 July 2019

I have a gunite pool with speckling.

in full sun the pool bottom looks fine and the speckling is multi colored with some dark blue.

when it is overcast and cloudy, there are patches on the bottom especially near the floor edges that look black.

The sides are fine in sun or shade.

Would/should black algae be noticeable even in full sun. This is confusing the heck out of me.

Thanks in Advance


InyoRob posted this 31 July 2019

It's easier to see them when the sun isn't reflecting off the surface. I would try using a silver algaecide. If it is black algae, the silver algaecide will kill it.