❤️ Cardinal Tetra (Paracheirodon axelrodi)

The Cardinal Tetra is often called the "king of tetras" and for good reason. While similar to neon tetras, cardinals have more extensive red coloring that runs the full length of their body, making them even more stunning. These peaceful schooling fish are a favorite for planted tanks and Amazon biotopes.

📋 Quick Facts

🆚 Cardinal vs Neon Tetra

• Red stripe: Cardinals - full length / Neons - half length
• Size: Cardinals slightly larger
• Price: Cardinals typically more expensive
• Hardiness: Cardinals prefer softer, more acidic water
• Temperature: Cardinals prefer warmer water

⚠️ Important Considerations

• Prefer soft, acidic water - Unlike neons, less adaptable
• Must be kept in groups - Minimum 6, prefer 10+
• Sensitive to water quality - Need stable parameters
• Add to mature tanks only - Not for new setups

🏠 Tank Requirements

• Tank Size: 20 gallons for a school
• Mature tank: At least 3 months cycled
• Plants: Heavily planted preferred
• Lighting: Subdued - shows colors best
• Dark substrate: Enhances coloration

Water Parameters

🍽️ Diet & Feeding

Omnivores that need variety.

• High-quality micro pellets/flakes - Staple
• Frozen daphnia - Excellent for color
• Frozen brine shrimp
• Frozen bloodworms - Occasional treat
• Live foods - Baby brine shrimp

Feed small amounts 2-3 times daily.

🐟 Compatibility

Good Tankmates

• Other tetras (Rummy Nose, Ember)
• Rasboras
• Corydoras
• Small peaceful plecos
• Dwarf cichlids (Apistogramma, Rams)
• Hatchetfish
• Pencilfish

Avoid

• Large fish - Will eat them
• Aggressive species
• Fish requiring hard water
• Angelfish - May prey on cardinals

🌿 Ideal Biotope Setup

• Blackwater with tannins (Indian almond leaves, driftwood)
• Dense plants (Amazon swords, Vallisneria)
• Dark substrate
• Subdued lighting
• Gentle flow

💡 Tips for Success

• Only add to mature, stable tanks
• Keep in large schools (10+) for best behavior
• Maintain soft, slightly acidic water
• Use dark substrate and dim lighting
• Quarantine new fish carefully
• Weekly small water changes

📚 Summary

Cardinal Tetras are the jewels of the Amazon - stunning, peaceful, and perfect for planted tanks. They're slightly more demanding than neon tetras, preferring soft acidic water and mature tanks. In proper conditions, their brilliant red and blue coloring makes them one of the most beautiful freshwater fish available.