How Many Cory Catfish Should Be Kept Together?

Cory catfish must be kept in a school of six or more. Cory catfish are shoaling fish that do best in groups. If shoaling fish are not placed and kept in large enough schools, they may become anxious and stressed. As a result, cory catfish would be susceptible to diseases and illnesses. 

It is of the utmost importance for aquarists to learn and remember that one should always keep corydoras (cory) catfish with others. Housing six cory catfish in a tank would be best. Perhaps you are eager to see your cories reach a long lifespan. In that case, you need to ensure that your tank provides the optimal living environment for your cories.

What Is The Number Of Cory Catfish That You Can Keep Together?

Keeping six cory catfish (or more) together would be the ideal scenario for your fish tank inhabitants. Grouping them is mainly because cory catfish are timid and naturally shoal in the wild.

Cories are known as shoaling fish, meaning they must to stay together for social reasons.

These shoaling fish have the instinct to live together and cannot live fully without their school. There is safety in numbers, and shoaling makes these fish feel secure.

They must be grouped, especially at night when they seek security. These fish are the happiest in groups. A stress-free fish is a healthy and content fish.

Some fish enthusiasts or hobbyists may only want to keep two or three cory catfish in smaller tanks. Although this may be an option, the cories cope much better when kept in larger groups. Keeping only one cory catfish is never advised.

Cory catfish are small and generally only need a little space inside a fish tank. However, they are highly social fish and favor swimming in schools.

Your best bet would be continuously working on housing six cories in your fish tank at any given time.

Two Spotted Cory Catfish Side by Side

Why Should Six Cory Catfish Be Kept In The Same Tank?

Cory catfish are a great addition to a fish tank due to their peaceful temperament and happy-go-lucky nature.

They get along well with other fish species in community tanks due to their calm, non-aggressive manner.

They are also a popular type of fish for aquarium fish. Still, the problem is that they prefer to avoid being kept by themselves. An isolated cory catfish would not thrive in an aquarium environment at all.

They are very social fish and feel safe, more comfortable, and at ease when part of a group.

Cory catfish live in large groups in the wild, and we must aim to create this realistic scenario in an aquarium too.

One needs to ensure a safe environment is created for the cories to live as they would in nature. Keeping six or more cory catfish together would cater to this safe setting for the fish to thrive.

Cory catfish should live as naturally as possible to live healthily, which is an integral part of the well-being of the fish.

Consider Tank Sizes When Keeping Cory Catfish Together

While the recommendation to always keep six cory catfish together will still stand, you may need to take the time to think about the sizing of each tank.

One must always aim for favorable conditions in the tank for your fish to thrive.

The size of your tank is just as important as the number of cories you should house in your aquarium.

Give careful consideration to the size of the individual tank. It would be best to ensure that your tank size is suitable to accommodate six or more cory catfish alongside any other fish you keep in the tank.

Usually, the number of fish kept in a single fish tank is based on several factors. These factors relate to variables such as tank size and the size of the fish you decide to keep.

As previously stated, keeping six cory catfish together is always best, so deciding on the most suitably sized tank would be wise.

The general rule is to house 1-inch-long adult fish size per one gallon of water.

To date, there are around 400 species of cory catfish. New species are still being found. All of the species range in size.

Aim to accurately choose the best-sized tank suited to the size of the particular species of cory catfish which you have chosen to keep.

Let’s explore various tank sizes that one could consider.

Two Cory Catfish with Bristlenose Pleco

Cory Catfish In A 10-Gal Sized Tank

A 10-gal fish tank is the bare minimum-sized tank that one could use to keep six cory catfish together. However, it is not usually recommended at all as it is considered to be too small.

Never consider a 5-gal fish tank, as this would be far too small for fish to thrive.

Cory Catfish In A 15-Gal Fish Tank

Smaller cories would be most suited to a 15-gal fish tank. Keeping six cories in this tank would be as similar as using a 10-gal fish tank.

Examples of smaller (dwarf) cories would be corydoras pygmeaus and corydoras hastatus.

The size and number of tank mates and filtration systems in your tank would also depict the space available for keeping six fish together.

Cory Catfish In A 20-Gal Fish Tank

Many species of cory catfish will need a 20-gal or more sized tank to thrive and live happily. This tank size is the most popular.

A size 20-gal tank also provides more options regarding the number of cories kept and the type of species.

Larger corydoras species, such as the bronze cory catfish or sterbai corydoras, would ideally suit this 20-gal tank.

It would be best to purchase a 20-gal long tank. A 20-gal long tank is better for cory catfish as these fish are the bottom dwellers of a tank and a long tank provides adequate space to dwell.

Cory catfish love to dawdle around the bottom of tanks as they look for bits of uneaten food.

Cory Catfish In A 30 – 50-Gal Tank

These sizes of tanks are also preferred as they are capable of housing rather large communities of fish. In these tanks, one could keep several types of cory species in different sizes.

It is always ideal to err on the side of caution by having plenty more space to house your fish.

Can Different Species Of Cory Catfish Be Kept Together?

We now know aquarists or fish hobbyists should keep six cory catfish together.

However, fish keepers should keep six of the same type of cory catfish together in the tank. Keeping six cories, each of a different cory species would be better.

It may seem like an option to keep two peppered, two pandas, and two albino cory catfish together. They may get along with each other in the tank.

The reason would be that these fish are placed together. The fish have no choice but to stay together in the tank.

However, your best attempt at mimicking their natural environment would be to keep the fish together in groups of their own kind.


You need to keep six cory catfish (or more) of the same species together in a suitably sized fish tank to form a reasonably sized school of fish. Keeping the fish in this number will entail that your cory catfish adequately live out their instincts and natural behaviors to live a full and healthy life in an aquarium setup.