Algae eaters are the automatic clean up crew in the aquarium. They show up for work everyday and are eager to do their job. Learn which algae eaters to employ and which ones to avoid!
Controlling algae growth in the freshwater aquarium is a task many novice hobbyists struggle with. Before you find the correct balance in water parameters and before the beneficial bacteria in your tank have time to establish themselves, you may find algae growing on your tank walls and decorations. In small quantities, algae is not a problem but if it is allowed to grow out of control it can take over the tank. In some cases, a quick burst in algae growth (often referred to as an algae bloom) is a sign of poor water quality. If you are simply looking for a way to control regular algae growth, however, the solution can be as simple as adding an algae eater to your tank.
What Algae Eaters Do in the Aquarium
Although some species of fish actually have the words “algae eater” in their name, this phrase is used generally to describe breeds of aquarium fish which feed on algae. Some algae eaters have suction cup like mouths that are perfectly designed for sucking algae off tank walls and aquarium décor. Other species belong more to the bottom feeder category, primarily scavenging for uneaten fish food, though they may feed on algae growths as well.
In the freshwater aquarium, algae eaters feed on various types of algae. Brown algae is the most common type found in new aquariums and it typically disappears on its own after the tank has stabilized. Green algae can be found in almost any tank but it grows more heavily in tanks with intense lighting or those exposed to natural sunlight. Hair algae looks like small green/gray strands and it is often overlooked by algae eating species of fish. Red algae, or brush algae, is stubborn and it is another variety that many algae eaters avoid.
Types of Algae Eaters
Plecostomus – The plecostomus, also called the pleco, is one of the most commonly used algae eaters in freshwater aquariums. These fish can grow very large, however, so it is unwise to use them in tanks smaller than 30 gallons. Plecos eat brown, green and brush algae but have been reported to eat other aquarium fish if they are small enough. Mature plecostomus have a tendency to become aggressive and territorial – they may latch on to the sides of other fish and may also destroy live plants in the aquarium. For these reasons, the common pleco is not recommended for the novice aquarist. There are smaller varieties, such as the Zebra Pleco (Hypancistrus zebra), but this particular species is very expensive - costing as much as $450.00! An alternative choice that's much easier on the wallet would be the Bushy Nose Pleco. Color variations for this species are orange, tan, and white (albino). The cost is in the neighborhood of $10 - $15.
Chinese Algae Eater – The Chinese Algae Eater is most effective when young – as these fish mature, they tend to grow lazy and subsist on algae wafers and uneaten fish food rather than scavenging for algae. These fish can grow up to 10 inches, though the average size is 6 inches, and they often become aggressive and territorial as they increase in size. Chinese Algae Eaters are suitable only for large community tanks and should be given plenty of hiding places among rocks and driftwood. These fish are also not recommended for the novice aquarist, and with the availability of better alternatives, many experienced aquarists will "pass" on putting these in the home aquarium.
Siamese Algae Eater – These fish go by the scientific name Crossocheilus siamensis and are very useful algae eaters in the freshwater tank. Many aquarists confuse the Siamese Algae Eater with the Chinese Algae Eater because both look very similar. However, the Siamese is a much better alternative and, unlike most algae eaters, this species eats thread algae and brush algae. Additionally, Siamese Algae Eaters may eat planarians, or flatworms, which can cause problems in the freshwater aquarium. These fish are best kept singly or in groups and they tend to do well in community tanks. Siamese Algae Eaters are not aggressive, but they are strong jumpers, so be sure to keep your tank covered if you intend to raise these fish.
Otocinclus Catfish – The Otocinclus Catfish, or Oto Cat, only grows up to 2" which makes it perfect for small tanks. This algae eater feeds on young algae rather than established growths and they seem to prefer brown algae. Unlike some algae eaters, Otocinclus can be picky when it comes to water conditions and it may take them some time to acclimate to the tank. Their preferred tank environment is densely planted with sand or gravel substrate and an already-established algae growth. These fish also prefer to be kept in groups. They are compatible with most community fish and are a favorite among many aquarium hobbyists.
Bristlenose Catfish – A relative to the common Plecostomus, the Bristlenose Catfish is one of the most popular types of algae eaters. They are also referred to as Bristlenose Pleco or Bushynose Pleco. These fish grow up to 6" and do well in community tanks. Though they tend to be peaceful and get along with all types of fish, it is not recommended to keep Bristlenose Catfish in a tank with large, predatory species. Bristlenose Catfish will feed on algae growth on tank walls and decorations, but their diet should also be supplemented with blanched green vegetables and/or algae wafers. Though these fish do not generally damage live plants, they may feed on Amazon Swords if not provided with enough fresh vegetables. Because of their relatively small size and their peaceful nature, this species makes a good choice for the home aquarium.
Tips for Caring for Algae Eaters
While some algae eaters may subsist mainly on the algae growth in your aquarium, it is wise to supplement their diets to ensure that they receive proper nutrition. Many hobbyists offer their algae eaters sinking pellets or wafers such as algae wafers or spirulina pellets. In addition to these commercial foods, some species of algae eater will also eat fresh vegetables. The Otocinclus, for example, may eat boiled zucchini and Plecostomus feed on a variety of vegetables. If you plan to offer your algae eater fresh vegetables, blanch them in hot water for a few minutes first. Do not leave the vegetables in the tank for more than an hour or it could negatively affect the water quality.