5 Effective Algae Eater Fish for Freshwater Aquariums

Estimated Read Time: 5 minutes

Algae is a natural part of any freshwater environment, but it can quickly become a nuisance.

If left unchecked, extensive algae growth poses a threat to the health of the fish.

But not to fear: Algae-eating fish are here!

In this post, you’ll discover the benefits of algae eater fish in an aquarium.

You’ll also learn about 5 effective algae controllers that thrive in freshwater environments!

Benefits of Algae Eater Fish in a Fish Tank

clean water in a serenity aquarium

This aquatic clean-up crew won’t remove all the stubborn algae, but they can reduce the amount that collects around the tank.

And remember, their clean-up service does more than meets the eye:

  • Algae Control
  • Improved Water Quality
  • Natural Filtration
  • Increased Oxygenation

1) Algae Control

An obvious benefit is the minimization of visible algae.

Algae-eating fish consume these plants as part of their diet, keeping algae growth in check for a more visually appealing environment.

2) Improved Water Quality

Excessive algae growth can lead to poor water quality by depleting oxygen levels and releasing toxins.

Simply put, algae eater fish help prevent algae from overrunning the tank, which improves your view of the habitat and the health of your fish.

3) Natural Filtration

As they consume algae around the tank, they break down excess nutrients in the water and convert it to waste.

Waste, along with any uneaten food, then gets processed by the tank’s biological filtration. This helps maintain a healthy nitrogen cycle.

4) Increased Oxygenation

Dense algae can decrease the oxygen levels in the water, posing a threat to the well-being of the fish.

Therefore, algae-eating fish help maintain a healthier and more comfortable environment for all aquatic life in the tank.


Now you see the benefits of including algae-eating fish, but they’re not a one-size-fits-all kind of solution.

Keep reading to see 5 of the most popular algae eater fish for freshwater fish tanks!

5 Popular Freshwater Algae Eater Fish

1) Bristlenose Plecostomus

bristlenose plecostomus feeding on an aquarium rock

Bristlenose Plecos, also known as Bushynose Plecos, are small, armored catfish with a sucker mouth.

They have a unique appearance with a flat body and bristle-like appendages on their head.

These Plecos are excellent algae grazers, consuming different types, including green spot algae and diatoms.

At Serenity, we specialize in cleaning freshwater aquariums in business facilities.

Due to the plecos’ small size, peaceful nature, and exceptional tank-cleaning abilities, it’s a tremendous addition to our clients’ tanks.

Plus, the Bristlenose is only one of our popular aquatic friends!

2) Siamese Algae Eater

Siamese Algae Eater eating algae on the substrate

Siamese Algae Eaters are known for their voracious appetite for many types of algae, making them highly effective at algae control in freshwater aquariums.

They have sleek bodies, vibrant colors, and distinctive black horizontal stripes.

These active and social fish are often included in aquariums for their calm demeanor and ability to consume both green and brown algae.

3) Otocinclus Catfish

Otocinclus Catfish eating algae of a leaf in a fish tank

Often called Oto Cats or Dwarf Suckermouth Catfish, these are small but mighty algae eaters.

The peaceful Otocinclus Catfish primarily feeds on soft green algae and is particularly effective at cleaning glass surfaces and plant leaves.

Oto Cats are best kept in groups to ensure their well-being and encourage natural feeding behaviors.

4) Nerite Snails

Nerite Snail eating algae off the glass of a fish tank

While they may not be fish, Nerite Snails need to be mentioned as they are highly efficient algae eaters.

These small, colorful snails have a spiral shell and are well known for their ability to devour algae on glass, rocks, and plant leaves.

They are peaceful and low-maintenance, making them one of the top choices for algae control in populated freshwater tanks.

5) Chinese Algae Eater

Chinese Algae Eater grazing the bottom of a decorated fish tank

Chinese Algae Eaters have a torpedo-shaped body and a distinctive golden coloration.

They are popular fish known for their ability to consume many types of algae, including filamentous and brush algae.

However, it’s important to note that Chinese Algae Eaters can become aggressive and territorial as they mature.

Research compatible tank mates before putting them in a community aquarium.

Choosing the Correct Algae Eater Fish

bristlenose plecostomus eating algae off aquarium glass with other fish and decor in the background

As we mentioned, not all algae-eating fish are built the same.

You can’t blindly place one in a tank and expect it to survive.

Here are a few things to consider:

  • The specific type of algae in a fish tank
  • Algae should be present before adding algae eaters
  • The compatibility of all the fish

The Specific Type of Algae in a Fish Tank

Some algae-eating fish will consume brown algae (diatoms), while others can only eat green algae.

For example, Bristlenose Plecostomas can feed on both brown and green algae, while an Otocinclus Catfish will only survive off of soft, green algae.

Do additional research on the water condition, temperature, and tank size before adding any of these fish.

Algae Should be Present Before Adding Algae Eaters

If you’ve just set up a new tank with little or no algae, you may want to wait to add in these fish.

For the best results, there should be a sufficient amount of algae already established.

Also consider that large tanks may provide enough for multiple algae eaters, while smaller tanks may only sustain one or none of them.

Nonetheless, there are a variety of fish foods for algae eaters, which keep them full when algae is limited.

The Compatibility of All the Fish

Algae eater fish are great for sprucing up an underwater habitat, but some can be aggressive with the other inhabitants.

Conduct additional research on your aquarium fish to ensure they’ll get along with each other.

It’s great to see a cleaner tank, but if the fish are constantly stressed and fighting, it’ll be much less enjoyable for everyone.

For help with this research, follow the links below to learn about specific tank mates:

Final Thoughts

By embracing the inclusion of algae-eating fish in your fish tank, you can create a harmonious and balanced ecosystem.

You provide your fish with a healthier habitat while you reap the benefits of reduced algae growth and improved water quality.


At Serenity USA, we work exclusively in the B2B space, offering spacious aquariums, vibrant fish, and routine cleaning services for our clients.

Looking for a hassle-free aquarium for your facility?