How Many Cory Catfish in a 10 Gallon Tank?

Cory catfish are one of my favorite freshwater fish. They just add life to any aquarium they’re added to. Unfortunately, the smaller your tank is, the more limited your options are for these fish.

A 10 gallon aquarium will hold a population of up to 8-10 pygmy corydoras, if you don’t add any other types of fish. You can also hold up to 8-10 hastatus or 8-12 habrosus corydoras. Avoid putting any of the larger species of cory catfish into a 10 gallon aquarium.

There are practically as many different opinions on this topic as there are people giving the opinions, so let’s discuss this in a bit more detail.

Corydoras | Source: Deposit Photos

Is a 10 Gallon Tank Large Enough for a Cory Catfish?

Whether or not a 10 gallon aquarium is big enough for a corydora is still the topic of quite a bit of debate on the internet. Some people say it is, others say you need at least a 20 gallon because of how active of swimmers they are.

Still other people say you need 10 gallons per cory catfish (which is just not true, especially since they need to be kept in groups of at least 6).

I’d say the best balance of evidence is to avoid keeping full sized corydoras in a 10 gallon aquarium. (Anything that gets over 1.5” long as an adult.) 

That would be ones like the following:

  • Sterbai Corydoras
  • Albino Corydoras
  • Panda Corydoras
  • Emerald Corydoras
  • Etc

What this leaves you with are the 3 dwarf cory catfish species. Not as big a range of choices, but it still does leave you with some options for putting cory catfish into a smaller tank.

Corydoras Pygmaeus | Source: Deposit Photos

Here is a table with those species and how many of them I think you can keep in a species only aquarium (or maybe with a population of red cherry shrimp).

SpeciesHow Many
C. Pygmaeus6-10
C. Habrosus6-12
C. Hastatus6-10

Out of the 3 species, the habrosus corys are the ones that will act most like regular sized corydoras, based on what I’ve heard from other people who own them.

I own pygmaeus corys, and they are an extremely shy species. Plus, they spend more time swimming mid tank. If you keep them, you may want to make sure you have a lot of places where they can hide.

I have a few stands of large fake plants, and they love hanging around them because they feel safe being able to hide in them if necessary.

By all accounts, including my own, these corys don’t act like the full sized ones very much.

Corydoras Habrosus | Photo 159015304 © jessica keras |

While I haven’t personally spoken to anyone who has owned corydora hastatus – they seem to be a rarer species – I’ve heard they’re more active, mid tank swimmers, and can also be pretty shy. Because of this, the same advice I gave for the pygmies would apply to these as well.

What Type of Cory Catfish is Best for a 10 Gallon

Let’s get straight down to what you’re probably wondering. There are all these different types I can add, but is one better than the others for my tank?

Corydoras Habrosus, also known as the salt and pepper pygmy cory catfish, is the best species of corydoras for a 10 gallon aquarium. They stay small, are less active swimmers than the other pygmy species, but still retain the behavior of larger corydoras.

That’s not to say that the other pygmy species aren’t suited for 10 gallon tanks, I just think habrosus corydoras are better choices.

Because they’re active swimmers, they won’t be as affected by the space constraints in a 10 gallon aquarium. Also, since you want a cory catfish, these will give you the behavior that cory catfish normally display.

The other 2 pygmy species act more like tetras than regular corydoras.

What are the Best Tank Mates for Cory Catfish in a 10 Gallon Tank?

If you’re going to add tank mates to your aquarium, I’d recommend reducing the number of cory catfish you’re keeping to somewhere between 6 to 8. This will give you more space for your other fish.

Tank mates for corydoras in an aquarium this small should be both small and peaceful themselves so that they don’t overrun your tank or attack your corydoras.

Here are some good options:

  • Ember Tetras – These small fish will be perfectly at home in a 10 gallon aquarium and add a deep red to your middle and upper tank sections.
  • Celestial Pearl Danios – These fish have a pleasant coloration and like to hang out mid tank mostly, though you’ll see them all over the place.
  • Emerald Dwarf Rasboras – These rasboras don’t get too big but still pack a lot of color.
  • Red Cherry Shrimp – Probably the best option for your 10 gallon due to their peaceful nature and low bioload. Common rule of thumb is that you can keep 10 shrimp per gallon, so you can maintain a nice population of RCS along with your cory catfish.
  • Blue Velvet Shrimp – A blue variation of red cherry shrimp.
  • Other Pygmy Cory Catfish Species – You can mix the 3 species as long as you keep at least 6 of each. This does mean that you have to pick 2, because you don’t have enough tank for 18 corydoras.

Whether you want to keep your corydoras by themselves or add in some other types of fish to spice your tank up, you’ve got a wide range of options, even beyond the few I just mentioned here.


You can absolutely keep corydoras in a 10 gallon tank, somewhere between 6 (no fewer than) and 12 of a single pygmy species. If you’re going to keep more than 8, it should be a species only tank. Otherwise, you can add other fish to the aquarium as well.

Avoid keeping any of the larger species of corydora, however. They get too big to put into a 10 gallon aquarium.

Good luck with your new fish!