Green Beard Algae can be a vary attractive addition to an aquarium with big pieces of stone and/or bog-wood. It forms a tick green carpet over the surface closer to the light source. It is very soft and slippery but it is impossible to be removed mechanically. It can also be seen on slow growing plant leaves. It grows approximately 3 cm and the growth is rapid. The best way to control this algae is with the Neritina sp Zebra snail that will eridicate it. Siamese Algae Eater, Plecostomus spp. are known to eat this algae as well as the Rosy barb and a very aggressive fish called the Red Tailed Shark. Keeping lights for more than 12 hours a day will trigger this algae as well as unbalanced nutrient. It will show up in planted tanks with low CO2 and NO3 levels. This algae can be found in low and high pH waters. Green Beard Algae is very common in non-planted aquariums.
Photo by Dusko Bojic.