The black algae in my pool does not look like the pictures on your website

by Jeff Jansen
(Pedasi, Panama)


I don't know if what I have in my pool is the black algae that you refer to on your website. I'm not even sure it's algae, but I assume that it is. It seems to have a thickness to it of maybe 1/32nd of an inch. It's round with a diameter of anywhere from 1/8 of an inch to 1/2 inch.

I followed instructions from your website I believe: raise ph, increase chlorine level, use 3x shock first, then shock once per week, and scrape the stuff off the side of my pool with a chlorine puck.

The black circles brush off the walls fairly easily, pretty much intact. The last time I attempted to get rid of the stuff, I vacuumed the stuff up right away and then flushed the filter.I thought I had the problem licked because I didn't see any of the black spots on the walls of my pool for probably about a month.

Then, all of a sudden they appeared again, only there was a lot more of it. As a matter of fact, each time I think I rid the pool of the problem, I end up with more of the spots than I had before I went through the process of trying to get rid of them. I suppose I broke them all apart and then there were many more spores to start growing.

By the way, I live in the country of Panama.

So, do I have some strain of black algae? It sure doesn't look like the black algae that I see on pool websites. Either way, do you have any recommendations?

Hi Jeff. What you're doing is partly correct. First is to reduce, not increase the pH. Chlorine is more effective at a lower pH. Next is to scrape off the heads using a wire brush, then go back and scrub the affected areas with a chlorine tab. You might be able to get a product that's called a Pentair Algae Gon Chlorine Tablet Holder. It fits on the end of a telescopic pole.

And last is to maintain a high FC level, up to 15 ppm if you can for a few days. You'll need to test the water AM and PM, add chlorine, and clean the filter at least once per day. Black algae is called the herpes of pools for a reason. Once you have it, it's there. We can only try to contain it and we never know when the next outbreak will occur, or what sets it off.

Black algae burrows into the surface and has tentacle like appendages. This is the reason that it's so difficult to remove. I've seen black algae roots that have burrowed 5" into the plaster and through the gunite.

Hope this helps and clarifies things for you.


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