Other Names: Bear algae, Brush Algae

Color: Bright green to blue-green to blackish green

Appearance
Belonging to the red algae family, beard algae grows on the edges of plant leaves as well as on the edges of almost any hard surface. Composed of very fine strands it grows in dense patches resembling a dirty green beard, thus earning the name beard algae. Rapid growing, it is soft and slippery, yet clings tenaciously to plants and cannot be easily removed by hand.

It is eaten by only a few fish, notably the Florida Flag Fish and the Siamese Algae Eater (Crossocheilus siamensis).

Cause

• Rhodophyta
• Contaminated plants
• Small strands in water of fish bag
• Digestive tract of fish

Beard algae most often enters the tank on contaminated plants, however even small free floating strands in a bag with fish are enough to start it growing in your aquarium.
 

Cure

• Bleach affected plants
• Remove affected leaves
• Stock tank with Siamese algae eater
• Treat tank with copper

Affected plants can be soaked for two to three minutes in a ten percent bleach solution to kill any algae on them. Completely remove heavily affected leaves. Bleach rocks, gravel, and any other items that exhibit growth of the algae. Stock the tank with a Siamese algae eater (Crossocheilus siamensis).
 

Note: Be sure to purchase the proper species, as many species of fish are sold under the name of Siamese algae eater. Other species of fish do not eat beard algae. If other options fail, treat with copper according to manufacturers directions.

However, copper can have adverse effects on certain plants as well as fish, and should be used with caution.

Prevention

• Quarantine new fish for 48 hrs
• Purchase plants & fish from reputable LFS
• Bleach new plants prophylactically

To avoid algae entering the tank via fish, quarantine new fish for at least two days. When placing them in the tank net the fish rather than dumping them out of the bag, so no bag water enters your tank. Soak newly purchased plants for two to three minutes in a ten percent bleach solution to kill any algae on them.