Cory Catfish Tank Size: A Complete Guide (+ Infographic)

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Most fish owners are puzzled as to how many fish they should add to their aquarium. So, if you are planning to keep Cory catfish in your home aquarium, you might wonder about the appropriate size of the tank. Don’t worry. This article will be a complete guide to keeping Cory catfish based on tank size for you.

In this article, I’ll go over different tank sizes and the appropriate number of Cory catfish for keeping in them. So, by the end of the article, all your confusion regarding the topic should be clear. Let’s start!

How Many Gallons Does a Cory Catfish Need?

Cory Catfish need a tank volume of at least 10 gallons to survive. However, a minimum of 30 gallon-sized aquarium would be ideal. It is because Corydoras are schooling fish. So, it would be best if you keep them in small groups in the household aquarium just as they stay in nature.


There are many different species of Cory catfish. And, they all might require a different amount of space to live their life properly. Now, I will go over the required tank size for a few most common species of Cory catfish that one can keep in their home aquarium:

  • Corydoras Julii

Julii Cory catfish is one of the most popular species of Cory catfish to keep in an aquarium. This species generally grows to be 6 cm or 2.5 inches long. So, you would require at least a 10-gallon tank. Nevertheless, if you want to give your Cory the best possible life, the size of the aquarium must be about 15 to 17.5 gallons.

  • Corydoras Bandit

An adult Bandit Cory catfish is around 5cm (2 inches) long. It would require a tank with a minimum capacity of 10 gallons just like the previous one. However, for the Cory catfish to live comfortably, the tank volume must be around 15 gallons.

  • Corydoras Pepper

The female Pepper Cory can grow about 7 cm or 3.5 inches in length, making it a significantly larger species. They require a minimum tank size of 15 gallons, but a tank size of 20 gallons is recommended for the perfect life.

How Many Cory Catfish In A 5 gallon Tank?

You should not keep Cory catfish in a five-gallon tank. It is because an aquarium size of 5 gallons would be too small for Corydoras to live their life comfortably. The bare minimum tank size for this fish is 10 to 15 gallons. So, try to maintain the tank when housing your cory fish.

As I have previously mentioned in the article, Corydoras are schooling fish. So, they prefer to stay in groups. And, it is best to keep at least six Cory catfish together to make them feel safe and sound. Since the average size of this fish type is around one to four inches, a 5-gallon tank won’t be adequate for Cory catfish.

Well, if you take into consideration the one gallon per one-inch rule in this regard, you might keep one or two Cory catfish in a tank of 5 gallons. However, there are many limitations to this rule since it does not consider the type of fish, the modern filtration system, and so on.

Moreover, fish, like humans, require space to swim. Some fish require more space than others. Even if the figures appear to be nice on paper, the aquarium might be too tiny for the fish to swim around freely. This is especially true in the case of active species, and also species that school.

It is a must to house multiples of schooling fish together, which necessitates greater space. Putting 1 or 2 schooling fish would simply cause the fish to get stressed, resulting in a shorter lifespan. The reason is fishes tend to live longer in their proper habitat. So, as a schooling fish, a tiny 5-gallon tank won’t be ideal for your Corydoras.

Read Also:- Can Cory Catfish Live With Shrimp?

How Many Cory Catfish In A 10 gallon Tank?

If you don’t have any other fish type, six Cory catfish in a ten-gallon aquarium should suffice. You will need a larger tank if you want to keep more Cories. The number also depends on how large the cory fishes are and their species as well. So the answer is not as clear-cut.

Well, the number you can keep in a 10-gallon tank won’t be the same for all Corydoras species. So, let’s take a look at the following table to know how many Cory catfish of a few species you can keep in an aquarium of 10 gallons:

TypeNumber of Corydoras (10-gallon tank)
Albino Corydoras4-6
Emerald Corydoras4-6
Dwarf Corydoras5-6
Threestripe Corydoras5-6
Julii Corydoras5-6
Bronze Corydoras5-6
Pygmy Corydoras6-8

How Many Cory Catfish In A 15 gallon Tank?

Since you can keep six Corydoras in a 10-gallon tank, you can easily put 8-9 Cory catfish in a 15-gallon tank. However, you can also keep fewer Cories in the tank to provide them much more space to swim around. You can never have too much space for cories.

But it is a must to keep a minimum of six Cory catfish together if you want to give them the best possible life.

If you want to keep other varieties of fish in the same tank, you should not keep more than six Corydoras in the tank. Since this species love to swim and move in a group, they won’t be able to live their life with comfort if they can’t get sufficient space. So, opt for a larger tank if you want to keep more cories or other types of fish in your tank.

How Many Cory Catfish In A 20 gallon Tank?

You may keep around 12 Cory catfish in a 20-gallon tank depending on the species, available space in the aquarium, and so on. Though there is a hard-pressed rule on how many you should keep. You can keep lesser cories together. But try not to go over 12 as it might be too congested for them. 

Keep in mind that the number will only be applicable if you don’t add any other fishes in your tank. If you want to add different types of fish or even different Cory species, a 20-gallon tank won’t be enough for 12 fish.

Well, a 20-gallon tank should not be a house for more than 12 Cory catfish. Besides, you will need to boost your tank’s capacity when you decide to add any rocks or plants. Moreover, you must check for all problems with your fish as soon as possible to treat them before they become worse.

How Many Cory Catfish In A 30 gallon Tank?

You can keep up to 18 Cory catfish in a 30-gallon tank. However, only add this amount of Cories if you are sure that you can maintain them properly. Failing to take care of your fishes will result in their illness and shortened lifespan. So, for beginners, it is advised to start with a small school.

It is preferable to preserve the available room in the aquarium for 5 to 7 Cory Catfish to be added as needed rather than starting a new tank. So, if you are planning to add more Corydoras in your tank in the future, don’t keep more than 10 Cories in your 30-gallon tank.

How Many Cory Catfish In A 50 gallon Tank?

You can keep more than 20 Cory catfish in a 50-gallon tank easily. But if you don’t have any previous experience of maintaining aquarium fish, it is best to avoid starting with such a large number. First, gather some experience, then start to add more Cories in your tank as per your expertise.

If you would like to keep a group of Cory cats in a communal tank with some other fish, a 50-gallon tank would be ideal for you. Furthermore, larger tanks are also more conducive to the growth of living plants.


In short, you can keep up to six Cory catfish in a 10-gallon tank. However, you can only keep this number of Cories if you don’t intend to add any other fish in the tank. So, if you want to add other types of fish or other species of Cories, it would be best if you get at least a 30-gallon tank.

I hope this article has served as a complete guide to keeping Cory catfish based on tank size. Remember that maintaining a group of Cory catfish together is just as crucial as providing them with an adequate living area. So, consider both to keep your Cories healthy and happy.

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