10 Best Algae Eaters for Freshwater Aquariums

You need help to control algae growth in your aquarium. In this top 10 list of amazing algae eaters, we’ve gathered animals that are not only safe for aquatic plants but can often work together for increased effectiveness.

Aquarium Co-Op is a wholesaler of thousands of live plants. We are committed to keeping them as healthy as possible. That’s why we utilize the most effective algae eaters in the aquarium hobby for our holding tanks. We have learned that every algae eater is unique and has the right mouth and body shapes to eat specific types of algae. We mix different types of algae eaters into our aquariums to eat the various kinds of algae. If you have a really large tank, start with just a few algae eaters on this list, adjust your tank lighting and plant nutrients, and wait a month to see what impact they have on the algae. You may need more help.

1. Reticulated Hillstream Loach

This oddball fish is one of the coolest-looking algae eaters you will ever see. The fish can grow to 3 inches (7.6cm), and it looks almost like a miniature stingray. It is covered in intricate black stripes and golden brown dots. Using their strong gripping abilities, they can easily clean large, flat surfaces like vertical aquarium walls, rocks, and broad plant leaves. They can be thought of as your personal window washers for algae and diatoms.

Loaches can sometimes be territorial and may try to dominate their species. To counter this, it is best to keep them in small groups of one or three loaches. If you can keep them in water coolers with a stable pH and feed them high quality sinking food like Repashy gel foods, you might see some baby loaches appear in your aquarium.

There are many species that live in hillstreams and brooks, including Beaufortia kweichowensis and Sewellia ligneolata.

2. Amano Shrimp

Hillstream loaches can eat flat types of algae well, but it may be necessary to have a faster-moving algae eater who can reach into tight spaces or cut off large chunks of fuzzy algae. Meet Caridina multidentata, a clear-brown dwarf shrimp that can reach 2 inches (5 cm) in length. These rare creatures will eat hair and black beard algae. Because of their small size, you will need at least four (or more) of them to make a difference in the growth of algae. The full species profile can be found here.

Amano shrimp will readily breed in your aquarium, but you won’t get any baby shrimp unless they are raised in saltwater.

3. Nerite Snails

We have many ornamental snails from the Neritidae Family. They are both adept at scavenging and eating alga. They are particularly adept at removing the toughest green spot algae, as well other algae that can be found on plants, driftwood and decorations. They are white and resemble a sesame seed-like egg, which means that they won’t hatch in freshwater unlike most aquarium snails. This will ensure that you don’t get an out-of control population. There are many varieties of snails to choose from, including red racer, zebra, horned and tiger. However, we prefer olive nerite because they are the most durable. For healthy shell development, don’t forget calcium!

Green Spot Alga is difficult to get out of rocks and plants. However, nerite snails can remove it and eat it.

4. Cherry Shrimp

One cherry shrimp, or Neocaridina darvidi, isn’t as effective at algae eating than an amano shrimp. The brightly-colored dwarf shrimp are easy to breed in home aquariums. With a decent-sized colony they can provide excellent preventative maintenance against excess food and algae. Their tiny limbs are perfect for picking through the substrate, plant roots, and other tiny crevices, and they’re happy to consume anything that’s digestible. At 1.5 inches (4 cm) long, cherry shrimp come in almost every color of the rainbow and can be easily sold for profit to your local fish store or other hobbyists. Read more about them in our cherry shrimp article.

An army of bright red cherry shrimp exploring a lush forest of green aquarium plants is a delightful sight to behold.

5. Otocinclus Catfish

The catfish of the Otocinclus genus are commonly known as otos or dwarf suckermouths because they typically stay around 2 inches (5 cm) in length. Their smaller, slender bodies allow them to fit into tighter spaces than other algae-eating fish. Like the hillstream loach, their mouths are ideal for eating diatom algae from flat surfaces, and you can find them usually hanging out on the aquarium glass or plant leaves. Otos are susceptible to becoming starved so be sure to give them lots of Repashy Soilent Green, as well as plenty of vegetables such as canned green beans and blanched zucchini pieces. For more information on how to care for these adorable catfish, read our full article here.

Otocinclus catfish are a schooling fish, so try to get at least three to six of the same species to help these shy creatures feel safe and comfortable.

6. Siamese Algae Eating

Crossocheilus oblongus (also known as SAE for short) is a 6-inch (15 cm) cleaner fish that is commonly used in larger aquariums. Their downturned mouths are well-suited for eating hair algae, black beard algae, and leftover scraps in the fish tank. Because SAEs have the ability to consume more algae than juveniles, it is not surprising that they eat more of the fish. Therefore, you may need to reduce food portion sizes in order to get older SAEs interested in eating algae again. SAEs, like hillstream loaches can be territorial with similar-looking species. To get more algae-eating power, you should either get one SAE or three.

Siamese algeaters are different from Chinese ones, which can be twice as aggressive and can eat twice as many plants.

7. Florida Flagfish

Jordanella floridae is also known as the American flagfish because of the male’s beautiful red stripes and rectangular shoulder patch that resembles the flag of the United States. This voracious algae eater, measuring 2.5 inches (6 cm), has the right mouth to eat hair algae, black beard algae, and other fuzzy alga types. It can however sometimes cause damage to delicate plant leaves. If you have an unheated tank with other fast-swimming tank mates, this killifish may be the right algae eater for you.

As a native of North America, flagfish can thrive in cooler water environments without any aquarium heaters.

8. Bristlenose Plecostomus

Although they are one of the most popular algae eaters, Plecostomus can grow to be quite large and not suitable for home aquariums. Thankfully, bristlenose plecos from the Ancistrus genus are peaceful catfish that stay between 4 to 5 inches (less than 13 cm), making them perfect for a 25-gallon tank or larger. Their suckermouths can be used to eat algae and vacuum up food crumbs. To ensure they receive all the nutrients necessary, you should feed them Repashy gel food, frozen bloodworms and sinking wafers.

Males are well-known for their bristles on the snout. Females, however, have a clean-shaven appearance.

9. Molly Fish

Mollies, a Poecilia genus livebearer, are a popular species that can live in both fully fresh and fully saltwater waters in the Americas. Because of their flat, grasping jaws and bottomless stomachs, they are constantly picking at algae found on plants, hardscape, and even flat surfaces. Their variety of fin shapes, colors, fin types, and patterns have been carefully selected by aquarium hobbyists. They are easy to reproduce when there is plenty of food and hiding places for their fry. As a heads up, fancy mollies are often raised in brackish water fish farms, so if you sense health problems with your new fish, consider adding aquarium salt and extra minerals to help them thrive.

10. Rosy Barb

Certain barbs such as the rosy barb (Pethia conchonius) have a taste for fuzzy algae like hair, staghorn, and thread algae. This relatively peaceful species grows to 3 inches (7.6 cm) long and comes in normal, neon, and long-finned varieties. Similar to the flagfish, rosy barbs can be kept in unheated aquariums with other speedy tank mates. Keep them in groups of 6-10 (preferably with more males than females) in a larger tank, at least 29 gallons.

Unlike most barbs, Pethia conchonius are relatively peaceful and won’t bother your other fish as long as you get a decent-sized school to keep them entertained.

Want more information on how to get algae under control? Read our complete article on the most common types of algae found in freshwater aquariums and how to get rid of them.