Black algae are the most aggravating variety of algae. Many individuals claim that once you have black algae in your swimming pool, it’s here for life, it does not disappear. That is not entirely true, but the difficulty in annihilation is due to the strong roots and protective layers over top of the black algae plant. Like yellow algae, black strains can emerge even in the presence of normal sanitizing levels and proper pool filtration.

A black algae is a thread-like growth on the rough surfaces of the swimming pool. Black algae will appear as dark black slippery spots on pool surfaces (walls and floor), and also forms a protective coating.

Black algae forms a layered structure where the first layer (which chlorine may kill) protects under layers from further destruction. Black algae are similar to the black algae that is found on bathroom shower tiles and in silicone seams near the bath. This form of algae is very slow growing but very hardy. It is extremely chlorine resistant