brilliant rummy

The Cardinal Tetra is a stunning freshwater fish prized for its vibrant coloration and graceful schooling behavior. It features a brilliant electric blue stripe running the full length of its body, paired with a vivid red band extending from head to tail—more intense than its close relative, the Neon Tetra. Native to the blackwater streams of the Amazon Basin, Cardinal Tetras thrive in soft, acidic environments and are a favorite for planted aquariums.

Cardinal Tetra (Paracheirodon axelrodi) – Complete Care Guide Description The Cardinal Tetra is a stunning freshwater fish prized for its vibrant coloration and graceful schooling behavior. It features a brilliant electric blue stripe running the full length of its body, paired with a vivid red band extending from head to tail—more intense than its close relative, the Neon Tetra. Native to the blackwater streams of the Amazon Basin, Cardinal Tetras thrive in soft, acidic environments and are a favorite for planted aquariums. Water Parameters Soft, acidic, and stable conditions are essential: Temperature: 25–29°C (77–84°F) pH: 4.5–6.5 Hardness: 1–6 dGH Tank Size: Minimum 60 liters (15 gallons) Water Flow: Gentle Water Changes: 20–30% weekly Care & Maintenance Cardinal Tetras are slightly more sensitive than some beginner fish: Keep in groups of at least 8–10 for natural schooling and reduced stress. Provide a heavily planted tank with driftwood and shaded areas. Maintain excellent water quality—they are sensitive to fluctuations. Use soft lighting and consider a blackwater-style setup. Feed a varied diet: high-quality micro pellets, flakes, and frozen/live foods (daphnia, brine shrimp). Ensure proper filtration but avoid strong currents. Behaviour & Temperament Extremely peaceful and social schooling fish. Active swimmers, primarily in mid-water levels. Display vibrant colors when kept in groups and low-stress environments. Non-territorial and non-aggressive. Can be shy if kept in small numbers or with aggressive tank mates. Compatibility Ideal for peaceful community aquariums with similar water requirements. Works well with other small, calm species. Avoid large or aggressive fish. Suitable Tank Mates Small tetras (Neon, Rummy Nose, Ember) Rasboras Corydoras catfish Dwarf cichlids (Apistogramma, Rams) Pencilfish Small peaceful gouramis Tank Mates to Avoid Large cichlids (Oscars, African cichlids) Aggressive or fin-nipping fish Predatory fish Very active or boisterous species Fish that require hard, alkaline water Pro Tips Add only to a fully cycled, mature aquarium—very sensitive to new tank conditions. Maintain soft, acidic water for best coloration and health. Use driftwood and leaf litter to replicate natural habitat. Keep nitrates as low as possible (<10–15 ppm). Acclimate slowly to avoid stress. A dark substrate and background enhances their colors significantly. Summary The Cardinal Tetra is a vibrant, peaceful, and elegant schooling fish that thrives in well-maintained planted aquariums. With stable water conditions, proper group size, and compatible tank mates, they create a stunning, colorful display that enhances any community tank.