Cardinal Tetra

The Cardinal Tetra is one of the most popular nano aquarium fish in the world. Known for its brilliant red and electric blue stripe, the Cardinal Tetra adds vibrant color and movement to planted aquariums. Because the Cardinal Tetra is a peaceful schooling fish, it thrives best when kept in groups and is an excellent choice for community tanks.

Native to slow-moving blackwater streams in South America, the Cardinal Tetra prefers soft, slightly acidic water and heavily planted environments. When kept in proper conditions with good water quality, this species displays intense coloration and natural schooling behavior that makes any aquarium look alive.

What We Like About the Cardinal Tetra

• Bright neon red and blue coloration
• Excellent nano schooling fish
• Perfect for planted aquariums
• Very peaceful temperament
• Great community fish

Recommended Tank Parameters for Cardinal Tetra

Tank Size: Minimum 60L (15 gallons)
Temperature: 24–28°C
pH: 5.5 – 7.0
Water Hardness: Soft to moderately soft
Lighting: Moderate lighting preferred

Stable water conditions are very important for Cardinal Tetra health. Sudden changes in water parameters can stress the fish and affect their color.

Cardinal Tetra Schooling Behavior

The Cardinal Tetra is a true schooling fish and should always be kept in groups. Keeping at least 6–10 Cardinal Tetras helps them feel secure and display natural swimming patterns. Larger groups often produce stronger colors and more active schooling behavior.

Cardinal Tetra Tank Mates

Because the Cardinal Tetra is extremely peaceful, it can live with many small community fish.

Good tank mates include:

• Rasboras
• Guppies
• Corydoras catfish
• Small peaceful tetras
• Otocinclus

Avoid aggressive or large fish that may see the Cardinal Tetra as food.

Are Cardinal Tetras Shrimp Safe?

The Cardinal Tetra is mostly shrimp safe.

• Safe with adult shrimp
• May eat baby shrimp (shrimplets)

If you keep shrimp in the same aquarium, adding moss and dense plants can help protect baby shrimp.

Cardinal Tetra Diet

In aquariums, the Cardinal Tetra accepts a variety of foods including:

• High-quality micro pellets
• Crushed flakes
• Frozen foods (daphnia, bloodworms)
• Baby brine shrimp

A varied diet helps maintain strong colors and healthy growth.