The deep brown algae and the red calcareous algae are very important species for reef growth. On the natural reef thay are known as reef-building algae because as thay grow thay bind together loose portions of the reef, making it a much more stable structure. In a aquarium thay perform the same sort of service and in addition to this the algae will cover much of the aquarium with attractive, sometimes plate-shaped, growths. These growths do not in any way disrupt or disturb the development of the hard or soft corals.
Apart from being attractive, these algae perform an important service by removing nitrate from the water and in addition, when thay are present in large quantities, can provide an extra haven for fish and invertebrates. When these algae are present in the aquarium they are good indication of general stabilization of the environment!