Black beard algae infects freshwater aquariums and spreads rapidly if not removed. The scientific name for the algae type is Audouinella. It also is known by a variety of other common names, including black brush algae and BBA. It is recognisable by its long, black strands that resemble hair. Black beard algae first appears in patches, but eventually develops into a thick carpet. Removal of black beard algae requires cleaning out the microscopic pieces as well as the larger established algae clumps from the aquarium.
Remove from the aquarium all rocks and decorative items that have black beard algae growing on them.
Fill a sink with a solution of 5 parts of water to 2 parts of bleach. Place the aquarium rocks and decorations into the water and allow them to soak for a couple of minutes. When the algae turns white, it's dead.
Pick up each aquarium item and scrub the surface thoroughly with a soft-bristle brush to remove the black beard algae from it.
Drain the water from the sink and rinse each item thoroughly in clean water to remove all traces of the bleach residue.
Place the rocks and decorative items back into the aquarium.
Examine all live plants in the aquarium for signs of the algae growth, and remove any infected leaves with your fingers. If entire plants are infected, remove them.
Add an algicide mixture to the aquarium water in the amount specified on the bottle. Algicide is available at aquarium and fish supply stores, and is safe to use around fish and plants.
Turn off the aquarium lights after they have been on for six hours per day. Lower light levels will help to prevent algae.
For ongoing black beard algae control, the Aquatic Community website suggests adding the following animals to your aquarium: Siamensis, Black Mollies, CAE/SAE Algae Eaters, Apple snails and Angelfish.