An algae eater is a type of fish, crustacean, or mollusk that consumes algae as a primary part of its diet. Algae eaters are used by aquarium owners to maintain a balanced tank environment. Common types of algae eaters include shrimp, crabs, bottom dwelling fish, and snails.
Each species of algae eater requires a different type of environment to survive. This includes fresh or salt water, differing water temperature, and a different pH balance. If the algae eater is originally from a habit with constantly moving water, it may need this habitat replicated using an electrical current generator in the tank. When choosing an algae eater for an aquarium, it is important to consider the other fish and types of plants that will share its living space. Some species of algae eaters are aggressive towards other fish, while other types are frequently eaten by larger fish.
There are different kinds of algae that include red, green, black, and hair-type. Certain species of algae eaters will eat any type available, while others prefer or require a specific kind. Some amount of algae in an environment can be necessary to maintain proper aquarium balance, so it may be preferable to have an algae eater that does not consume all algae available.
One common type of algae eater is the otocircus catfish, which typically stay under two inches (5 cm) in size. The catfish is not aggressive to other fish, eats brown and green algae, and may be eaten by larger cichlid fish that share its tank. Another type of algae eating fish is the nocturnal plecostomus, which has brown patterned skin, eats plants, and is aggressive towards others of its species. The plecostomus is nocturnal, and it requires a dark place to hide during daytime hours. Plecostomus have been known to latch on to larger fish, eating algae and debris directly from the fish's skin.
The Siamese algae eater is a fish unique in that it will eat red, black, and hair algae not commonly consumed by other species. This fish is identifiable by a black stripe that runs down its back all the way to the tip of its tail, and its clear colored side fins. Siamese algae eaters may be aggressive towards other fish and tank inhabitants, and they also eat plants.
Sea urchins can also be algae eaters, and they have been known to strip an environment completely clean of any presence of algae. Snails can be used to remove algae in crevices that other fish will not reach. Two types of shrimp that eat algae are the Amano shrimp and the cherry shrimp. Both are sensitive to copper, and the amano shrimp will also eat left-over food found floating in a tank. Hermit crabs are also used to clean algae in an aquarium, however some types may be aggressive towards other fish.