Hi.
I'm a pool owner, but due to family health issues, the pool was closed and not maintained for 5 years or so. We opened it this year with the pool company that has cared for it for the past 25 plus years. It was a muddy mess. Pool was drained and power washed, then filled with clean water and seriously shocked two or three times. The pool is plaster over gunite. We also have successfully used Caribbean Clear for years and never had any chemistry or algae problems over those years.
The pool has lots of little raised black dots in it, and yellow stains. Doing a google search, a friend came up with black algae. The pool company folks said it was not black algae but gunite coming through the plaster. I asked for a test of this. They nuked the pool with chorine and then began scrubbing with a wire brush. I had been scrubbing with a wire brush for several days to prepare for this shock and awe treatment. The little black raised dots did not move and did not fade. Pool company said that if it was black algae, the brushing would have caused the algae to have a cloud in the water. There was no cloud. Pool company said this proves its plaster that has been worn through and the many small black bumps are gunite. They also said that continuing to use the metal brush would further erode the plaster. They said the pool is safe to swim in, but it doesn't look too great.
On this forum, I read that a test for black algae is to scrape some off with a fingernail and smear on a white paper towel. If it's black algae, it will look dark green. I could not scrape any of the black bumps off at all, even with a metal brush. The bumps feel sharp, and trying to scrap with my fingers got me no where.
My daughter has autism and immune issues. Even though the pool company that we have worked with for 20 plus years says this is not black algae, I'm still not convinced. I've read about the possible health issues associated with black algae and am afraid to let anyone in the family swim in the pool until we're sure what the black dots are. Given the heat of the summer, this is really disappointing for all of us.
I'll try and attach some files. Any help you can offer is greatly appreciated.
The two files I attached are from today. This is the first time I've seen the redish "dust" in the pool.
Thank you!
I'm a pool owner, but due to family health issues, the pool was closed and not maintained for 5 years or so. We opened it this year with the pool company that has cared for it for the past 25 plus years. It was a muddy mess. Pool was drained and power washed, then filled with clean water and seriously shocked two or three times. The pool is plaster over gunite. We also have successfully used Caribbean Clear for years and never had any chemistry or algae problems over those years.
The pool has lots of little raised black dots in it, and yellow stains. Doing a google search, a friend came up with black algae. The pool company folks said it was not black algae but gunite coming through the plaster. I asked for a test of this. They nuked the pool with chorine and then began scrubbing with a wire brush. I had been scrubbing with a wire brush for several days to prepare for this shock and awe treatment. The little black raised dots did not move and did not fade. Pool company said that if it was black algae, the brushing would have caused the algae to have a cloud in the water. There was no cloud. Pool company said this proves its plaster that has been worn through and the many small black bumps are gunite. They also said that continuing to use the metal brush would further erode the plaster. They said the pool is safe to swim in, but it doesn't look too great.
On this forum, I read that a test for black algae is to scrape some off with a fingernail and smear on a white paper towel. If it's black algae, it will look dark green. I could not scrape any of the black bumps off at all, even with a metal brush. The bumps feel sharp, and trying to scrap with my fingers got me no where.
My daughter has autism and immune issues. Even though the pool company that we have worked with for 20 plus years says this is not black algae, I'm still not convinced. I've read about the possible health issues associated with black algae and am afraid to let anyone in the family swim in the pool until we're sure what the black dots are. Given the heat of the summer, this is really disappointing for all of us.
I'll try and attach some files. Any help you can offer is greatly appreciated.
The two files I attached are from today. This is the first time I've seen the redish "dust" in the pool.
Thank you!
