10 Best Algae Eaters for Freshwater Aquariums

If your aquarium is covered with unsightly algae, you need some hungry helpers to get the outbreak under control. 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.

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. 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. To eat different kinds of alga, we use different species of algae eaters. 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. This list has more information about how to get additional 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. They can clean flat surfaces such as rocks and vertical aquarium walls. Think of them like your personal window washers for diatoms and other flat kinds of algae.

They can sometimes be a little territorial toward their own kind, so it’s best to get either just one loach or at least three loaches in a group to even out the aggression. 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 of hillstream and brook loaches, such as Sewellia lineolata, Beaufortia kweichowensis, and Gastromyzon ctenocephalus.

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). This rare animal will eat black hair and beard algae. However, they can only be fed a limited amount. Due to their small size, a group of at most four or more will be needed to reduce the growth of algae. You can read the full species profile for more information on how to care for them.

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

Coming from the Neritidae family, we have a very diverse group of small, ornamental snails that are adept at both scavenging and eating algae. They’re especially handy at scraping off the very tough green spot algae and other algae found on plants, driftwood, and decor. 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 spots algae can be very hard to get off rocks and plants. But nerite slugs are one of few animals that can do it.

4. Cherry Shrimp

If you did a direct, head-to-head comparison, a single cherry shrimp (or Neocaridina davidi) isn’t as efficient at algae eating as 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 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 made for devouring algae, vacuuming up food crumbs, and keeping 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. Their flat grasping jaws, flat stomachs, and ability to pick at any type of algae, regardless of its surface or hardscape, make them a popular livebearer. 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 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.

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.