How to Care for Cory Catfish? Guide for Beginners

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As a novice aquarist, you want to prioritize useful fish species over the purely esthetical ones. And nothing screams useful more than a hardy, peaceful, and efficient cleaning species like the catfish.

While this fish is generally easy to maintain, it does have its unique requirements to consider.

Today, we will discuss everything involving the Corydoras to help you craft the ideal setup for it.

Best Tank Size for Cory Catfish

Corydoras only grow up to 4 inches, but most of them remain smaller than that. So, the fish doesn’t need too much space. One catfish can do just fine in a 10-gallon setup, although you’ll most likely go larger than that.

These cleaning fish are great additions to any community environment thanks to their easy-going attitude and sociable demeanor.

Don’t go below 10 gallons, despite what others might advise. A 5-gallon nano tank isn’t enough to accommodate the catfish properly.

This shy bottom dweller requires a specific habitat to remain comfortable and at ease.

So, you need to provide your fish with various rock structures for hiding, live plants preferably, and a thick substrate for it to bury itself when necessary.

Corydoras are also more active than other bottom dwellers because they exhibit surface breathing.

Unlike bettas that do that thanks to their labyrinth organ, Corydoras showcase so-called intestinal breathing. In short, they assimilate oxygen via their thinner intestinal wall with direct access to capillaries.

So, despite being small, Corydoras demand at least 10 gallons per specimen. You can then increase the tank size by 1 gallon of water per 1 inch of extra fish.

Ideal Temperature for Cory Catfish

Corydoras enjoy moderate waters with temperatures around 70-78 °F. This is the ideal range to allow Corydoras to adapt to any community setup with tropical and even cold-water fish.

Despite the easy-to-achieve temperatures, a heater is necessary to keep water temperatures stable and your Corydoras happy and healthy.

What to Feed Cory Catfish?

Corydoras rank as omnivorous scavengers, given that they prefer to look for their food around the substrate. They eat anything they can find, including detritus, plant matter, worms, insects and insect larvae, etc.

In a tank, they will also consume food leftovers that other fish miss, making Corydoras easy to satisfy from a dietary perspective.

That being said, they also require additional sustenance to remain healthy and happy.

You have a variety of options in this sense, including shrimp pellets, algae wafers, and even the occasional protein snacks in the form of bloodworms or daphnia.

Protein snacks should be kept to a minimum, once or twice a week at most. Also, tweak the feeding frequency and meal size according to your fish’s size and appetite.

Most Corydoras will do just fine with one meal per day and sufficient food for them to eat in 3-5 minutes. Corydoras eat slower than other species.

How to Treat Sick Cory Catfish?

Corydoras aren’t particularly sensitive or prone to specific conditions but aren’t immune either. If your cory catfish shows signs of sickness, you must act fast.

Your goal is to identify the disorder fast because even mild-looking conditions can turn deadly fast.

In this context, consider the following steps:

  • Quarantine – This is the first necessary step, no matter the symptoms your catfish exhibits or their severity. You have no idea whether the disorder is contagious or not, so quarantining the fish is always the smarter move. This will protect the general fish population and allow you more control during the treatment.
  • Diagnose – Now is the time to diagnose the catfish’s problem by assessing its symptoms. If your catfish struggles with a health condition, it’s most likely a parasitic, fungal, or bacterial infection. The symptoms will vary from one condition to another; checking your fish closely should inform you of the nature of the disease. For example, rugged fins indicate fin rot, white or blurry eyes may insinuate a fungal infection, while bulgy eyes with swelling heads suggest bacterial infections.
  • Treatment – The treatment varies, based on the nature of the disorder. You need to use specific antibiotics to counter the problem. Penicillin and tetracyclin are common antibacterial medications in these scenarios, but you should always consult a vet before going in on the drugs.
  • Care requirements – The sick catfish needs to receive optimal care while being housed in the hospital tank. Change 15-25% of the water daily, provide nutritious food, and remove waste and food leftovers as often as possible. Water quality should be pristine to speed up the fish’s recovery.

Corydoras are hardy fish, so they should bounce back fast, especially if the treatment is timely and effective.

If the fish doesn’t get better after 1-2 weeks of treatment, you need to consider euthanasia as your best option left.

You can’t afford to reintroduce the sick fish into the main tank and risk the safety of other tank inhabitants.

Can You Keep Cory Catfish in Community Tank?

Yes, you can. Corydoras are great for community setups, so long as you follow several key approaches, such as:

  • Avoid aggressive and territorial species – Aggression and territorial behavior come in all shapes and sizes. They’re not exclusive to large fish since smaller species can also exhibit antisocial behavior. Pea puffers are the perfect example in this sense. These fish are less than 1 inch in size but can be quite the pest due to their aggressive and overly violent demeanor. Such fish can’t hurt your catfish physically because Corydoras are armor-plated, so they fear almost no one. But they can stress them out, which comes with different health issues. Stay away from violent and territorial fish, no matter their size.
  • Ensure sufficient space – We’ve already discussed this point, but we need to restate it. That’s because it’s normal for novice fish keepers to get carried away and stock too many fish in a too-small tank. No fish likes overcrowding, especially since the phenomenon comes with a variety of environmental problems. Overcrowding stresses even the most peaceful fish, leading to territorial and food-related fights and causing excessive accumulation of fish waste. And it’s easier to overcrowd fish in community tanks because each fish comes with different space requirements. You need to do some logistics work beforehand to figure out the best setup in this sense.
  • Mind the size difference – If the Corydoras’ tankmates are too large, your catfish can become prey, despite their armored skin. If their tankmates are too small, the Corydoras themselves will turn predators. Corydoras don’t usually exhibit predatorial behavior, but they won’t refuse an easy meal either. So, make sure that their tankmates are close in size to prevent aggression on either side.
  • Environmental requirements – This goes without saying, but you should mind the different environmental requirements of all fish. Many novice aquarists make the mistake of pairing incompatible fish species simply because they bought them based on how they look. This can be a costly mistake, not necessarily in terms of money, but in terms of time and effort invested in trying to make things work. Always research your fish before buying them to make sure that they’re compatible on all fronts.

Some compatible tankmates include mollies, guppies, swordtails, and even adult snails and some species of shrimps and crabs.

Regarding snails, always go for adult specimens because Corydoras can eat the smaller ones.

How Many Cory Catfish Should You Get?

Corydoras can live solo, but they thrive in cory-specific communities. You should ideally get around 6 of them in the same tank.

Corydoras will instinctively form a tight school, making them feel safer and happier overall.

You can easily set up a cory-only tank, so long as you provide your catfish with sufficient space, enough food, and an optimized layout.

The food part is especially important, given that your Corydoras will compete over the same space.

Are Cory Catfish Good for Beginners?

Yes, Corydoras are great for beginners. They are relatively low maintenance and can easily adapt to a community setting, provided you ensure optimal living conditions.

They are also hardy and resilient, so you shouldn’t have problems with them falling sick too often.

To provide your Corydoras with the best life possible, consider the following:

  • Ensure easy access to the water surface since these fish breathe atmospheric air occasionally
  • Offer your catfish a balanced diet with weekly protein snacks to keep them full and satisfied
  • Clean and maintain the environment in good conditions
  • Pair them with compatible tankmates and keep Corydoras in groups for a plus of safety and comfort

These are all accessible strategies that even novice fish keepers can attend to.


Corydoras are easy-going fish with charming personalities and a great presence.

Offer them a soft substrate for digging purposes, a balanced and healthy environment, and the company of each other, and they will thrive.

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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