How Many Corydoras Catfish Should I Get?

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Having several Corydoras in your community tank is nothing short of necessary. These cleaning catfish are essential additions to any aquatic setup, whether it’s a single-species environment or a community one.

But can you keep multiple Corydoras in the same aquarium?

The short answer is yes. To go beyond that, not only that you can, but you should. Let’s see why that is.

Why do Corydoras Need to be Kept Together?

It all comes down to the fish’s overall behavior and social tendencies. While Corydoras can live just fine alone, they prefer the company of other members of their own species.

These fish showcase visible social tendencies and preferences as they eat and rest together and protect each other from intruders.

Catfish feel safer in groups, especially when resting. It’s important to have several of them, especially in a community setup with multiple fish species populating the environment.

But, as you may suspect, the situation is more delicate than it might seem.

You need to reach a certain balance when housing multiple corydoras in the same tank.

We’re talking about the number of fish, the male-to-female ratio, the tank size, the layout, the feeding schedule, etc. So, let’s discuss all these aspects!

How Many Corydoras Should You Keep?

The number of cory catfish to keep depends on the breed, available space, and whether there are other fish species around or not.

Generally speaking, corydoras do great in groups of 5-6 individuals with at least 1 male present.

This is important because Corydoras also breed better in groups of at least this size than in pairs or small groups.

What Tank Size Do Cory Catfish Need?

You require at least 20 gallons for a group of 5-6 specimens. You may even consider 30 gallons, depending on the catfish’s size and whether you have a species-only or a community setup.

When it comes to figuring out the optimal tank size for your corys, consider the following:

  • The need for hiding places – Corydoras are docile, peaceful, and timid, and most breeds like to rest during the day. They will become more active at night when feeding, interacting with each other, and exploring their habitat. But they need resting places during daytime which also function as safe zones whenever the fish feels stressed or scared. Rocks, driftwood, and various decorations will fill that role perfectly.
  • Open space – Corydoras are scavenging bottom dwellers that are known as substrate diggers. They will sift sand through their gills to collect organic matter for eating and even bury themselves in the substrate occasionally. This helps them calm down when stressed or rattled – a behavior that’s even more noticeable in wild catfish. So, your catfish tank should also have open swimming spaces with a lot of naked substrates available. Make sure you avoid sharp rocks, pebbles, or any other item that could hurt the catfish’s sensitive skin, barbels, or gills. Plain, fine sand should do.
  • Easy surface accessLive plants are great for a cory catfish tank, but having too many live plants is not ideal. That’s because Corydoras tend to swim to the water’s surface from time to time to breathe. These catfish perform what’s called intestinal breathing, which is more prevalent in poorly oxygenated environments. In short, the fish takes in surface air via its mouth and metabolizes the oxygen at the intestinal level thanks to the surface capillaries in the intestinal tract. So, make sure that the live plants decorating the tank won’t prevent the fish from getting to the water’s surface.

Naturally, you should also account for any other fish you plan to add to the tank later. Make sure there’s sufficient space for everyone to prevent territorial fights or stress.

Also, don’t keep more than 6 corydoras in a 20-gallon setup. These fish are calm and peaceful but can get stressed and even aggressive when overcrowded.

You should also avoid housing more than one male per tank unless you have a lot of space and numerous hiding areas available.

Male Corydoras are more prone to fighting, especially during the spawning season.

Can You Keep Different Types of Corydoras?

There’s plenty of conflicting information regarding this topic, so I’ll lay it out plainly. Yes, you can house different Corydoras breeds in the same environment.

The only tips to consider in this case include:

  • Make sure that the fish are of similar size
  • Make sure that they have similar temperaments since some species are grumpier than others
  • Make sure that all Corydoras have similar colors since catfish use visual inputs to recognize their own

You should also adapt to your catfish’s different dietary and environmental requirements.

Look for breeds that share similar diets and water parameters for ease of cohabitation.

Do Cory Catfish Get Lonely?

Yes, they do. You may not notice the signs, but they’re there. Lone Corydoras may live shorter lives and face parasitic and bacterial infections more often than those living in groups.

They will also exhibit a more timid temperament, unlike catfish that get to socialize and benefit from a more uplifted mental state.

Corydoras that live in groups are less prone to stress, have stronger immune systems, look happier, and are more active in their habitat.

Can I Keep Just One Cory Catfish in a Community Tank?

Yes, you can, but be wise about it. Everything starts with the understanding that Corydoras are social animals, so they naturally orbit towards groups.

If you only have one Corydoras, for whatever reason, at least pair it with similarly-colored fish. Wild Corydoras are known to exhibit social connections with fish of different species as well.

Tetras are a good example in this sense. Have a group of tetras in your catfish tank, and the Corydoras may join the small swimmers occasionally when exploring their habitat.

Always house your cory catfish with small and peaceful species like platies, mollies, guppies, plecos, and others that won’t bother or bully the catfish.


Corydoras require the presence of other catfish to feel safer and at ease in their habitat. Consider investing in a catfish group and providing them with a personalized habitat that they can enjoy.

Your catfish will repay you with their joyful presence and unparalleled cleaning services, making them ideal for peaceful community setups.

Author Image Fabian
I’m Fabian, aquarium fish breeder and founder of this website. I’ve been keeping fish, since I was a kid. On this blog, I share a lot of information about the aquarium hobby and various fish species that I like. Please leave a comment if you have any question.

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