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. 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 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. Loach from 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 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.

Sometimes they can be territorial towards their own species, so you should only get one or three loaches per group. You might be able to see baby loaches in your aquarium if you keep them in cool water with a stable pH.

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. 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. Because of their small size, you will need at least four (or more) of them to make a difference in the growth of algae. For more details on their care requirements, read the full species profile here.

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

We have many ornamental snails from the Neritidae Family. They are both adept at scavenging and eating alga. They are especially adept at removing tough green spot algae as well as other algae on plants, driftwood, or decor. Their white, sesame-seed-like eggs won’t hatch in freshwater, unlike other aquarium snail types, so there is no need to worry about an out of control population. While there are many beautiful varieties to choose from (e.g., tiger, zebra, horned, and red racer), we personally like olive nerite snails because they seem to be the hardiest. 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. These brightly colored dwarf shrimp can be kept in small aquariums and provide excellent preventative maintenance to keep algae and excess food from growing. 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. 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 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 eater

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 2.5-inch (6 cm) voracious algae eater has the perfect mouth for ripping out hair algae, black beard algae, and other fuzzy algae types, but it can sometimes damage more delicate plant leaves in the process. 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 are one of the most well-known algae eaters, but they often get very large as adults and aren’t suitable for the average 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. To ensure they receive all the nutrients necessary, you should feed them Repashy gel food, frozen bloodworms and sinking wafers.

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, which are popular livebearers of the Poecilia genera, live in full freshwater to fully saltwater 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. 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.