Cardinal vs. Neon Tetras - Planted Tank Mates
Large group of Cardinal tetras in a planted tank.

Cardinal vs. Neon Tetras


When exploring the world of nano fish, everyone has stumbled across the fact that there’s a difference between a Cardinal vs. Neon Tetras.  Both display vibrant colors and look great under various lighting conditions.  They also have a tendency to keep with their group and shoal when kept in high numbers.  If you have a larger fish with a group of tetras, the tetras will cluster to create a colorful experience.  While one is a great beginner fish, the other is a little more delicate and requires tighter water parameters.  At a very minimum you should have at least 6 and aim for a 10 gallon tank.  If you want a stronger shoaling effect, aim for 20 or more. 

Neon Tetras (Paracheirodon innesi)

Neon Tetras are great beginner fish.  The reason is because they can tolerate both acidic and low alkaline water conditions. This makes them hardier than Cardinal Tetras and a bit easier to keep. Their size is also smaller in comparison, approximately 1-” 1.25″ max.  You’ll find them in almost every local fish store including commercial big box retailers.  You can read more about Neon Tetras here and compare their parameters side by side.

Neon tetra fish (Paracheirodon innesi).
Neon Tetra Fish – available on Amazon

You can spot a Neon Tetra right away with the red color markings only coming halfway up their body.  The red marking is always near the tail while the blue occupies the front head area.  In total, they’re a little less vibrant than Cardinal Tetras, but do show a combination of iridescent blue, silver and red coloring.  They shoal in groups to feel safe and comfortable from larger fish or predators.  It’s often said that they thrive and do best with large groups and lots of plants to hide.  Not to be confused with schooling fish because they don’t swim with synchronization, nano fish shoal in groups for safety and security.

Cardinal Tetras (Paracheirodon axelrodi)

Cardinal Tetras require a more experienced fish keeper.  They’re very sensitive to water changes and require softer to neutral waters.  They’re able to reach 2” in size and the red & blue markings run the full length of their body.  You can check out their parameters here and compare their parameters side by side.

Cardinal tetra fish (Paracheirodon axelrodi).
Cardinal Tetra – available on Amazon

Because they can be difficult to breed, some local fish stores offer wild caught Cardinal Tetras.  Habitats in Columbia and Venezulas have rainforests that alternate through high and low flood seasons.  During the dry season, water levels are low enough for local fishermen to passively collect fish and sell to the aquarium distributors.  Fish can often get caught in low-drying puddles and die, making this seasonal catch a more sustainable approach.  Many locals who make a living collecting aquarium fish depend on a clean and thriving rainforest, so it promotes conservation.  Wild caught Cardinal Tetras can actually be a bit of a controversial topic, so hopefully this bit of information can help you make your educated decision.

Cardinal Tetras also shoal, not school.  Their colors pop out a lot more under aquarium lighting, especially with custom settings that highlight the blue and red colors.  They can be a bit skittish, so approach your aquarium tank slowly.

All Things Considered

You can’t go wrong with either fish.  If you want 20+ fish but are on a budget, Neon Tetras are the way to go.  If the vibrant colors are important and you’re experienced at maintaining stable water parameters, Cardinals are a great option.  There isn’t a better fish when talking Cardinal vs. Neon Tetras, at least this helps you distinguish them to make a choice.


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