Do Cory Catfish Eat Algae? (3 Algae Eating Catfish Included)

Excess algae in your freshwater aquarium might appear as a greenish layer over the glass walls. Some people like to add algae eater fish or snails to manage the overgrowth of algae and help keep the tank clean.

While there are plenty of ways to reduce and prevent the growth of algae in your tank, will the addition of Cory catfish help?

Do Cory Catfish Eat Algae?

The short answer is no. Cory catfish do not eat algae that naturally grows in the aquarium walls or other decorations. Cory fish are bottom feeders but still do not prefer to eat algae. 

However, you will find that they will eat sinking algae wafers if you choose to feed them. But they will not go out of their way to eat algae, especially when other food is present. If the algae growth in your tank has just begun or if you’d like to prevent algae growth before it begins, Cory catfish fish are helpful there. 

But if you welcome Cory catfish to the fish family with the intention of getting rid of algae that’s already blooming, you’ll be disappointed. 

Do Cory Catfish Clean The Gravel?

Gravel is not suitable for Cory catfish, and they are better off in the sand. Since they are bottom feeders, Corys like to sift through the sand for small worms and bugs. But gravel might bruise their mouth or jaw.

What Kind of Catfish Eat Algae?

As we mentioned earlier, Cory Catfish won’t help much to rid the tank of algae. But there are a few catfish that will happily spend all day sucking algae and cleaning your tank. We’ve listed a few of the same that require the same tank size and water quality as Corys. They’ll also get along with Cory catfish and with each other if kept in the same environment.

Otocinclus Catfish

Otocinclus Catfish
Photo: danscapes90

Otocinclus Catfish, also known as “Dwarf suckers” or oto catfish, are identified by the armor-like coating on their bodies and their underslung suckermouths. They are pretty shy and easily frightened by most other fish. However, they are much more friendly with Corys despite their reserved nature. 

Oto catfish are known to enjoy and prefer algae over other foods. However, you can also feed them with algae wafers and fresh veggies like small pieces of zucchini. Yet, they prefer algae even in the presence of these foods. 

Just keep in mind that adding a couple of these fish would not be enough to clean the tank of algae. They are so small that the amount of algae they eat will be significantly minimal compared to bigger algae eating fish. 

Still, you can add the oto catfish along with other friendly catfish to get a clean tank, along with well-fed fish in the process.

Bristlenose Plecos

Bristlenose Pleco

The Bristlenose Pleco is a gentle-tempered fish that gets along with all other fish harmoniously. If you need a fish that frees your tank from algae, this one would be a perfect addition to your aquarium. 

Plecos are sometimes also called “vacuum” fish because they are known to gobble all the algae they can find. The main diet of this fish consists of algae which is why you’ll never find any as long as they are in the tank. 

If you plan to get Plecos, note that despite most of their food coming from algae, they also need other food for balanced nutrition. A few feedings of bloodworms and algae wafers are enough for Plecos to thrive in your aquarium happily.

Twig Catfish

Another fish you can add to your tank is the Twig Catfish or Farlowella acus. These catfish grow to around 13 to 15 cm in length and need a 20-gallon tank in order to survive. They are peaceful and calm bottom dwellers and get along well with Corydoras catfish

Like Oto catfish and Bristlenose, they also enjoy feeding on algae, which is the main component of their diet. You can even feed them vegetable-laden wafers or bloodworms occasionally. But usually, they prefer to clean out the algae before eating anything else.

However, even though they are one of the best fish for removing algae, they need a lot of care and maintenance. Twig catfish also require a tank with high levels of oxygen along with clean and fresh water. Since they are a bit shy in nature, it’s best to place them with other accommodating and peaceful fish.

More Ways To Beat Algae in Your Fish Tank

Avoid Direct Sunlight 

Excess sunlight in the tank contributes to algae overgrowth. So, consider shifting the tank to a place where there isn’t direct sunlight most of the day. Generally, the tank should be exposed to light for not more than 8 hours per day. And, if you are using artificial light, it would be better to reduce the intensity to prevent algal blooms.

Add Live Plants

Adding plants to the tanks will foster competition for nutrients and sunlight, thus starving the algae and preventing its growth. A tank with plenty of plants and few fish will reduce the growth of algae naturally. Alternatively, taking off plants from the tank environment will increase algae formation.

Clean Tank And Change Water Periodically

In natural conditions, freshwater is constantly introduced, diluting the nitrate levels before they reach harmful proportions. In a closed tank, a weekly introduction of new water is ideal. Remember that the entire water cannot be changed suddenly because fish will find it challenging to adapt quickly.

Avoid Overfeeding The Fish

Some over-enthusiastic fish owners love to feed their fish more than twice a day. We know how much fun it is to watch them gather around in a feeding frenzy over morsels of food. But overfeeding the fish with extra food to spare often encourages algae growth. The uneaten fish food increases the phosphate level in the water, which is the perfect environment for algae to thrive.

Final Thoughts

We hope you now have a better idea about how to deal with algae in your tank. If you are facing excess algae formation, try a few of the ideas given above instead of introducing Cory catfish to the tank. 

If you already have Cory in the tank, you can bring in a few algae-eating fish or snails, which will keep the tank clean.

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2 thoughts on “Do Cory Catfish Eat Algae? (3 Algae Eating Catfish Included)”

    • Hi Bonnie,

      Siamese Algae Eaters (Crossocheilus oblongus) are often used to manage hair algae and black beard algae growth. They can grow up to 6 inches (15 cm) in length, so they are best suited for larger aquariums.

      Moreover, juvenile SAEs tend to eat more algae because the larger adults can obtain food from other fish in the aquarium.

      These fish may also display some territorial behavior towards their own or similar-looking species. Therefore, it is recommended to keep either one individual or at least three in a group to enhance their algae-eating capabilities.

      Hope this helps!
      Ivan Yeoh


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