How Fast Do Cory Catfish Grow? {4 Growth Factors Explained}

Are you watching and waiting for your cory catfish to grow to their full size? How fast do cory catfish grow?

Is there a concern that your cory’s growth is stunted for some reason?

In this article, we’ll discuss how long it takes for cory catfish to grow in your aquarium.

How Fast Do Cory Catfish Grow?

Corydora catfish are smaller than most catfish and will reach an average length of 2 inches.

Some cories grow larger, but the growth process will take between 9-12 months and sometimes longer depending on:

  • tank size
  • gender
  • water quality
  • the amount of food they consume

Which Factors Influence The Growth Of Cory Catfish?

If you want your cory catfish to grow to their full potential, you’ll have to consider the following four factors:

  1. Tank size
  2. Gender
  3. Water quality
  4. Amount of food

1. Tank Size

We are told that 1 gallon of water per cory catfish will suffice to host them in your tank. If you place 10 cory catfish in a 10 gallon, you are running the risk of overcrowding. The limitation of movement may stunt their growth and you won’t see them reach 2 inches or more in length.

Corydoras don’t grow naturally if they don’t have the space to grow. You will have to be proactive and move them into a larger tank before they show a need or display any signs of stress from overcrowding or feeling cramped.

2. Gender

Cory catfish can reach sizes above 3 inches in some cases, but more often that not, it will be a breeding female that gets to that size. Females are broader or rounder. Look behind their gills to notice a chunkier build that usually makes it obvious that you’ve got a female cory catfish.

3. Water Quality

A cory catfish that is living in ideal water parameters will be healthier, happier and potentially grow fast and larger. Perform frequent water changes up to 50% weekly if you notice that your cory catfish are stunted or stopped growing.

Make sure the water temperature isn’t too warm or the dissolved oxygen in the tank won’t be enough to flow through their bloodstreams. If you notice your cory catfish coming up to the surface multiple times per minute, you know that they need more oxygen.

  • Keep the temperature steady at 75°-76°F.
  • Add an aerator.
  • Test parameters to keep nitrates below 5-10 ppm. 
  • Ammonia and nitrites should always be at 0 ppm.
  • Perform up to 50% water changes weekly.

4. Amount of Food

If you have a group of cory catfish, it will hard to deliver an equal amount of food to each one. The larger sized cory catfish in the group will find its to eat more than the others on most occasions.

It’s important to feed them often, but to also be present during feedings. After about 5-10 minutes, all leftovers should be removed, if possible, to maintain the water quality.

You can also add more enriched supplements to their food to boost their growth. Vitamin based or garlic liquid solutions could be used by dipping live or frozen food into a cup mixed with tank water before feeding them to your cory catfish.

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When Will My Cory Catfish Reach Full Size?

Most people enjoy the diminutive size of cory catfish compared to koi or larger catfish breeds. They are quirky, cute and peaceful. You have most likely acquired your cory catfish at 2-3 months of age.

  • At this point you will have to wait at least 9-12 months longer for them to reach their full size.

Just because half or more of the group has reached 1.5-2 inches, it doesn’t mean they all will. Not all cory catfish are the same, even if they are the same type or breed.

Allow for this variability as long as the smallest cory catfish in your group is still eating regularly and not spending most of its day isolated, sluggish or hiding.

How Big Can A Cory Catfish Get?

Breeding female cory catfish can reach over 3 inches.

  • The average size is 2 inches, but many people enjoy keeping healthy and happy cory catfish at or around 1.5 inches in length.
  • The bearded cory catfish is referred to the barbatus breed that could reach up to 4 inches.
  1. If you are keeping a type of cory catfish known to grow larger in size, it’s best to proactively place them in a larger tank before they outgrow a smaller one.
  2. Once they are too large for a smaller tank of 5-10 gallons and you notice it, it may be too late. The growth spurt may have been halted or stunted.

When your cory catfish has no more room to grow in the small tank, it may slow down its growth process. Switching to a larger tank at this point may not spark new growth.

Which Cory Catfish Are The Biggest?

The following list is based on our accounts and research, but we welcome your thoughts and opinions. We hope you can prove that your cory catfish that is not mentioned in this list, should be included because of its size.

If you are providing high quality food, a larger sized tank, ideal water water quality and keeping more females than males, you have a greater chance of having larger than average sized cory catfish, regardless of breed.

This is our order of the biggest cory catfish on average:

  • Barbatus Cory
  • Emerald or Green Cory
  • Elegant Cory
  • Bronze Cory
  • Peppered Cory

How Many Cory Catfish In A 20 Gallon Tank?

The answer depends on the type of tank. You should be looking for a 20 gallon long tank. How many cory catfish in a 20 gallon long tank is a suitable question for these active swimmers.

  • Between 8 and 10 Cory Catfish may live in a 20 gallon long tank.

Depending on the kind and other fish in the tank. Small species like dwarf cory catfish are capable of forming larger groups of 10–14 fish in the same amount of space.


Cory catfish will grow faster in larger tanks with plenty of water changes and a variety of high quality foods. Make sure the substrate is smooth to not wear down their barbells and keep them healthy while they grow.

Feed your cory catfish near the end of the evening when it’s time to turn out the lights. They enjoy feeding at night due to their tendencies to be more active at night compared to other fish in your tank. There will be less competition for food at this time if other tankmates are full or resting.

Females will grow larger than males and it’s best to stock your tank with a female to male ratio of 2:1 at least or else the males will chase around the females, stress them out and perhaps stunt their growth.


We hope your cory catfish live and grow to their full potential in your tank. Thanks for visiting us and see you again soon for the next cory catfish article that may be of interest to you. 

Brian Arial

Brian Arial has kept fish for leisure and worked with fish stores for most of his life. He enjoys writing and caring for aquariums and ponds.