Cardinal Tetra

Cardinal Tetra, scientifically known as Paracheirodon axelrodi, is one of the most admired nano schooling fish for freshwater aquariums. Its bright electric blue line paired with a rich red band running almost the full length of the body creates a striking effect, especially in planted tanks with dark substrate and soft lighting. This species is best suited for aquarists who want a peaceful, active shoal that brings constant movement and color to a community setup.

These tetras look their best when kept in groups rather than singly, as schooling behavior helps them feel secure and display more natural movement. Cardinal Tetras are a great fit for planted aquariums, blackwater-style layouts, and calm community tanks with other small, non-aggressive fish.

Key Features

• Appearance: Slim-bodied tetra with a luminous blue stripe and a vivid red lower body extending from head to tail.
• Size: Usually sold as small aquarium-ready fish and can grow up to around 4 to 5 cm in adulthood.
• Colors: Brilliant metallic blue with intense red coloration that becomes more impressive in healthy, stress-free conditions.
• Lifespan: With stable water quality and proper feeding, Cardinal Tetras can live around 3 to 5 years in home aquariums.
• Temperament: Peaceful, social, and ideal for community tanks; should always be kept in a school.
• Water Type: Freshwater species that prefers clean, well-maintained water with gentle flow.

Care Requirements

• Tank Size: A minimum of 45 litres is recommended for a small school, though larger tanks provide better swimming space and more stable water conditions.
• Water Parameters: Best kept at 23 to 28°C with a pH of about 5.5 to 7.0. Soft to moderately soft water is generally preferred.
• Diet: Accepts quality micro pellets, crushed flakes, and small frozen or live foods such as daphnia, baby brine shrimp, and bloodworms in moderation.
• Tank Mates: Suitable with rasboras, other peaceful tetras, small gouramis, corydoras, pencilfish, and gentle planted-tank companions. Avoid large or aggressive fish.
• Schooling Need: Keep at least 6, but a group of 10 or more gives a fuller display and reduces shyness.
• Care Tips: Stable water quality is important. Acclimate slowly, avoid sudden temperature or pH swings, and provide plants or driftwood cover to help them settle quickly.

Cardinal Tetras are especially popular for aquascaped community tanks because their color stands out beautifully against green plants and natural hardscape. For best results, maintain them in a calm, mature aquarium and keep them in a proper school so they show confident, synchronized swimming behavior.