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.

At Aquarium Co-Op, we’ve sold thousands of live plants, and one of our main concerns is keeping the plants as free of algae as possible. For our holding tanks, we use the most efficient algae eaters from the aquarium hobby. One of the most important lessons we have learned is that each algae eater has its own mouth and body that is best for eating certain types of algae. We mix different types of algae eaters into our aquariums to eat the various kinds of algae. If you have a large tank, only use a few of the algae eaters from this list. Adjust your tank lighting and plant nutrients and then wait for a month to see if they have an impact on the algae. If you need additional help, consider getting more clean-up critters from this list.

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. Think of them like your personal window washers for diatoms and other flat kinds of algae.

Sometimes they can be territorial towards their own species, so you should only get one or three loaches per group. Keep them in cooler waters with a stable pH, feed them high-quality sinking foods like Repashy gel food, and you may be lucky enough to see some baby loaches pop up in your aquarium.

There are many species for hillstream and brook loaches like Sewellia lineolata and Beaufortia kweichowensis.

2. Amano Shrimp

Hillstream loaches are excellent at eating flat types of alga, but you might need an algae eater with a smaller reach that can cut through fuzzy algae or reach narrow spaces. Caridina multidentata is a clear-brown dwarf shrimp, which can grow to 2 inches (5 cm). These rare creatures will eat hair and black beard algae. 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. 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. Unlike most other types of aquarium snails, their white, sesame seed-like eggs will not hatch in fresh water, so you don’t have to worry about an out-of-control population boom. 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. 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 Spot Alga is difficult to get out of rocks and plants. However, nerite snails can remove it and eat it.

4. Cherry Shrimp

A direct comparison of the two species would show that a single cherry shrimp (or Neocaridina Davidi) is not as efficient at eating algae as an amano. 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 legs are ideal for digging through soil, roots and other small crevices. They will happily eat any food that is 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. Learn more about cherry shrimp in our article.

A delightful sight to see is an army of brightly colored cherry shrimp in a lush forest filled with green aquarium plants.

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 SAEs have the ability to consume more algae than juveniles, it is not surprising that they eat more of the fish. In order to encourage older SAEs to eat more algae, you might have to reduce their food portions. 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 algae eaters are not the same as Chinese algae eaters, which are much more aggressive and can get twice as big.

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

Plecostomus is one of the most famous algae eaters. However, they can get quite large and are not suitable for a home aquarium. 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 are designed to consume algae, clean up food crumbs and keep driftwood clean. However, remember to feed them a well-rounded diet of sinking wafers, frozen bloodworms, and Repashy gel food to make sure they get all the necessary nutrients.

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

9. Molly Fish

Mollies, which are popular livebearers of the Poecilia genera, live in full freshwater to fully saltwater in the Americas. They are able to grasp and grab any kind of algae on any surface, including plants and hardscape. They can be bred into many different colors, patterns, fin types and body shapes by the aquarium hobby. If they are given enough food and hiding places, they will reproduce easily. 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 like the rosy bar (Pethiaconchonius) are fond of fuzzy algae such as 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. You can reduce aggression by keeping them in groups of six to ten (ideally, with more females than men) in a tank that is 29 gallons or larger.

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.

Need more tips on getting 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.