HomeFreshwater FishFreshwater Aquarium BasicsCardinal Tetras vs Neon Tetras Comparison (9 Different Keys)

Cardinal Tetras vs Neon Tetras Comparison (9 Different Keys)

In this article, National Park Aquarium are going to compare two of the most popular freshwater aquarium fish species – Cardinal tetras and Neon tetras. We will cover their similarities and differences in appearance, temperament, diet, and care requirements.

Hopefully, by the end of this article, you will better understand which of these two fish would be a better fit for your aquarium. What to know about Cardinal and Neon tetras.

Cardinal Tetras and Neon Tetras Overview

Cardinal Tetras
  • Family: Characidae
  • Colors/Patterns: Bright neon stripes in blue and red.
  • Size: 2 inches
  • Tank size: 20 Gallon (75 Liters)
  • pH level: 4.6 – 6.2
  • Temperature: 73 – 81°F (23 – 27 °C)
Neon Tetras
  • Family: Characidae
  • Colors/Patterns: Bright neon streaks in blue with red tail.
  • Size: 1 – 1.5 inches
  • Tank size: 10 Gallon (38 Liters)
  • pH level: 7
  • Temperature: 68 – 79°F (20 – 26 °C)

Cardinal Tetras vs Neon Tetras Comparison

cardinal tetras vs neon tetras infographic

1. Neon Tetra and Cardinal Tetra Origin

  • Cardinal tetras are native to the South American countries of Brazil and Peru.
  • Neon tetras, on the other hand, are native to the South American country of Colombia.

This difference in location can impact the availability and cost of these two species. In general, it’s easier to find and care for neon tetras than cardinal tetras. This is because neon tetras are widely available and relatively easy to care for, while cardinal tetras are less common and require more specialized care.

Neon Tetra and Cardinal Tetra Origin
Neon Tetra and Cardinal Tetra Origin

2. Appearance

When it comes to appearance, cardinal tetras and neon tetras are both attractive fish. Both types of fish have bright red bodies with a blue line running along the side of their bodies.

Additionally, both species display iridescent colors on their fins that shimmer and change color in response to changes in light. So if you’re looking for an eye-catching addition to your aquarium, either cardinal tetras or neon tetras may be a good choice.

  • Neon tetras: They get their name from their bright blue and green coloration, caused by a reflective layer of cells called iridophores.
  • Cardinal tetras: They are among the most popular freshwater aquarium fish due to their vibrant red coloration and relatively peaceful nature. Cardinal tetras are slightly larger and have a more stout body than neon tetras. Cardinals have a vibrant red coloration on their fins and tail.

Neon Tetra vs Cardinal Tetra Appearance

3. Behavior

Cardinal tetras are relatively peaceful fish but can be nippy towards slower-moving tank mates. They should not be kept with larger fish that may see them as food.

Neon tetras are even more peaceful than cardinals and make great tank mates for small community aquariums.

4. Sexual Dimorphism

  • Cardinal tetras are sexually dimorphic, meaning that males and females can be distinguished by their appearance. Males are typically smaller than females and have longer fins. In addition, the red coloration on the body of males is usually more intense than that of females.
  • Neon tetras are not sexually dimorphic. Both sexes have rather similar body sizes and fin lengths. The only way to tell males and females apart is by looking at their genitalia, which is impossible without special equipment.

One major difference between these two types of fish is that cardinal tetras are schooling fish and do best when kept in groups of three or more individuals.

On the other hand, Neon tetras tend to fare better as singletons or in small groups of no more than six fish. So if you’re looking for a peaceful community tank that’s easy to care for, cardinal tetras may be a better choice than neon tetras.

Neon Tetra Fish
Neon Tetra Fish

5. Cardinal Tetra vs Neon Tetra Size

The cardinal tetra tends to be significantly larger than a neon tetra, at about 2 inches long compared to 1 inch for the neon. This can make it an unsuitable choice for a small home aquarium that holds only one type of fish.

The different sizes also affect how these two species behave around each other. Since cardinal tetras tend to be more aggressive than neons, they are more likely to bully neon tetras, especially in a small tank.

In general, it’s best to avoid mixing cardinal tetras with fish that are much larger or smaller than they are.

On the other hand, Neon tetras can do well with a wider range of tank mates because of their small size.

Cardinal Tetra Fish
Cardinal Tetra Fish

6. Habitat and Care

  • Both of these fish come from the tropical rainforests of South America and require similar water conditions.
  • They should be kept in an aquarium with clean, fresh water that is well-filtered and has a temperature between 72-79 degrees Fahrenheit (22-26 degrees Celsius).

A sandy substrate is best, along with some rocks and plants for hiding places. These fish are social creatures and do best in schools of at least six, but ideally more.

7. Diet

Both cardinal and neon tetras are omnivorous and will eat various foods, including live, frozen, and flake options.

Therefore, it is important to provide a varied diet to ensure good health and vibrant colors.

Neon Tetra and Cardinal Tetra Diet
Neon Tetra and Cardinal Tetra Diet

8. Ease of Care

When it comes to care requirements, there are a few differences between cardinal tetras and neon tetras.

  • Both species require an aquarium at least 15 gallons in size. Still, a 20-gallon tank or larger is recommended for optimal stability.
  • They also require good water quality, so it is important to regularly perform water changes and closely monitor water parameters.
  • Both cardinal tetras and neon tetras require a varied diet full of protein-rich foods like brine shrimp, bloodworms, daphnia, and insects.

However, you should be aware of a few key differences between these two species.

For example, cardinal tetras prefer a slightly warmer temperature than neon tetras and require a higher quality of water.

In addition, cardinal tetras are less tolerant of changes in their environment than neon tetras.

As a result, it’s important to be extra careful when caring for cardinal tetras.

Learn about: Tetra fish care guide (tips to keep your fish healthy)
Ease of Care
Ease of Care

9. Breeding

Cardinal tetras are relatively easy to breed, while neon tetras can be challenging. As a result, you may need specialized equipment and plenty of patience to breed neon tetras successfully.

However, suppose you do have the right setup and experience. In that case, it is possible to breed both cardinal tetras and neon tetras at home.

Source: Izabella AquaZone


Cardinal and neon tetras are both beautiful, brightly colored fish that make great additions to a freshwater aquarium.

Given proper care and tank conditions, either type of fish can make a great addition to your home aquarium!

When choosing between cardinal tetra vs neon tetra, it is essential to consider what other fish will be in the same aquarium. Whichever fish you choose, be sure to do your research and provide them with the proper care to ensure a long and healthy life. Thanks for reading!

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Further Reading
Kevin Mills, the founder of Nationalparkaquarium.org


-- Founder --

I'm Kevin Mills, the founder of Nationalparkaquarium.org, where I share my deep passion for aquariums and aquatic life. With over 20 years of experience in fishkeeping, covering everything from tending to saltwater and freshwater tanks.

Kathleen Wood


-- Interrogator --

Kathleen Wood, a seasoned marine biologist, possesses a wealth of knowledge and experience in her field. Her research on tropical fish biodiversity spans over three decades, and she has contributed numerous scientific papers on aquatic life.