Rummy-nose tetra

The rummy nose tetra is a highly popular, peaceful freshwater fish native to South America. They are widely celebrated as one of the tightest schooling fish in the aquarium hobby. Growing to about 2 inches (5 cm) in length, they feature a vibrant red-orange face, a striking black-and-white striped tail, and a torpedo-shaped silver body.

Their bright red faces serve as a natural water quality indicator. When the fish are healthy and the water parameters are stable, their faces glow deep red. If they are stressed, sick, or if ammonia or nitrite spikes, their faces will fade to a pale pink or gray, warning the keeper to test the water immediately.

pH & Hardness: Prefers soft, slightly acidic water with a pH of 5.5 to 7.0, though they can acclimate up to 7.5.
School Size: Keep a minimum of 6 to 8 fish, though a group of 10 or more reduces stress and promotes tighter schooling.
Diet: Omnivorous. They happily eat high-quality flakes, micro-pellets, and frozen treats like daphnia or brine shrimp.

Aquarium Care Summary

Tank Size: Minimum 20 gallons (or a wide tank at least 24 inches across) to give the school room to swim.
Water Temperature: Warm tropical water between 74°F and 82°F (23°C – 28°C).