Black algae are single-celled organisms that grow in large colonies. They contain chlorophyll like other algae, but they also contain compounds that mask the green colour. It forms in cracks and crevices on pool surfaces (especially plaster finishes) and can grow somewhat protected from the surrounding environment due to the formation of a protective layer on the outside of the cell. This makes black algae more difficult to treat and it is somewhat resistant to normal chlorine levels.

• Use ALGAE KILLER as it kills black and green algae in swimming pools
• Use MSA II as it kills all types of swimming pool algae and resistant algae

IMPORTANT NOTE: Brushing is extremely important when treating black algae because that protective layer has to be broken in order for the sanitizer or algaecide to come in contact with the cells.

1.  Maintain a sanitizer residual of 1-3ppm
2.  Do an initial and weekly application of a preventative algaecide (such as BACK UP Algae Inhibitor)
3.  Shock routinely
4.  Make sure there is adequate circulation and filtration
5.  Brushing surfaces is vital