10 Best Algae Eaters for Freshwater Aquariums

You need help to control algae growth in your aquarium. This top 10 list includes animals that can not only be safe for your aquatic plants, but also work well together to increase their effectiveness.

Aquarium Co-Op has sold thousands of live plants. One of our primary concerns is to keep the plants free from algae. We use the best algae eaters available in the aquarium hobby to maintain 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. In order to be able to eat all types of algae, we have a variety of algae eaters that we keep in our aquariums. If you have a large tank of fish, it is a good idea to start small with only a few algae eaters. Then, adjust your tank lighting, plant nutrients, and wait for the results. Consider adding more of these clean-up critters to your tank.

1. Loach in Reticulated Hillstream

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 like a miniature Stingray, with its intricate black stripes and golden-brown dots. Because of their gripping power, they are able to clean large, flat surfaces such vertical aquarium walls, rocks, or broad plant leaves. Think of them like your personal window washers for diatoms and other flat kinds of algae.

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 for hillstream and brook loaches like Sewellia lineolata and Beaufortia kweichowensis.

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. Caridina multenttata, a clear-brown dwarf squid that can reach 2 in (5 cm) length, is here. They are one of the rare animals that will eat black beard algae and hair algae, but only if you don’t feed them too much. Given their small size, you’ll need a group of at least four of them (or even more) to make a significant dent in the algae growth. You can read the full species profile for more information on how to care for them.

Amano shrimp can be easily bred in an aquarium. However, you won’t get any baby shrimp until they are raised in saltwater.

3. Nerite Snails

A Neritidae family of small ornamental snails, this group is very diverse and adept at both scavenging as well as eating algae. They’re particularly skilled at removing difficult green spot and other algae from plants, driftwood, decorations, and other materials. The white, sesame seed-like eggs of these aquarium snails will not hatch in freshwater. You don’t need to worry about an out of control population. Although there are many options, including red- and yellow-colored zebra, red racer, zebra, and horned varieties, we prefer olive nerve snails. We think they are the hardest. Just don’t forget to provide extra calcium in the water (using crushed coral or Wonder Shell) and in their diet (using nano food blocks) to help with healthy shell development.

Green spots algae can be very hard to remove from plants and rocks, but nerite slugs are one of few animals that can do it.

4. Cherry Shrimp

One cherry shrimp, or Neocaridina darvidi, isn’t as effective at eating algae than an amano shrimp. However, these brightly colored dwarf shrimp breed easily in home aquariums, and with a decent-sized colony, they provide excellent preventative maintenance against the buildup of 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. Find out more information about cherry shrimps in our article.

An army red cherry shrimp patrolling a forest of green aquarium plants makes for a beautiful sight.

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. Their mouths, similar to the hillstream loach’s, are perfect for eating diatom alga from flat surfaces. You can usually find them hanging out on aquarium glass or leafs. Otos are prone to being underfed, so make sure you give them plenty of Repashy Soilent Green and vegetables like canned green beans and blanched zucchini slices. 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 the aquarium is large enough for the adult fish, SAEs tend to eat more algae than the juveniles. To get older SAEs to eat algae again, you might need to reduce the amount of food they eat. SAEs are territorial and may be territorial with other species. If you want to increase your algae-eating power, get at least three of them together.

Siamese Algae Eaters are not as aggressive as Chinese, and can grow twice as large.

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) in length, has the mouth to eat hair, black beard, and other fuzzy algae types. However it can also cause damage to delicate plants. 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

Plecostomus is one of the most famous algae eaters. However, they can get quite large as adults so are not suitable for small 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 make it easy to eat algae, clean up food crumbs, or keep driftwood clean. Make sure to give them a balanced diet that includes Repashy gel foods, frozen bloodworms, and sinking wafers to ensure they get all the nutrients they need.

Males have bristles around their noses. While females are more clean-shaven, Males are also known for having a cleaner face.

9. Molly Fish

Mollies are popular livebearers from the Poecilia genus that live in fully fresh to fully salt water in the Americas. They are able to grasp and grab any kind of algae on any surface, including plants and hardscape. The aquarium hobby has selectively bred them into a wide range of colors, patterns, fin types, and body shapes, and they readily reproduce if given plenty of food and hiding spots for the 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

Some barbs, like the rosy barb (Pethiaconchonius), are attracted to fuzzy algae, including hair, staghorn, thread algae, and others. 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. If you want to reduce aggression, keep your rosy barbs in groups of 6-10 fish (ideally more females than males) in an aquarium that is at least 29 gallons in size.

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.

You want more advice on controlling algae? Read our complete article on the most common types of algae found in freshwater aquariums and how to get rid of them.