Care guide
Caring for tetras
This guide covers Cardinal tetra and the other species that need the same care. Ask the seller about anything particular to Cardinal tetra.
- Adult size
- About 4 cm
- Water temperature
- 23–29 °C
- pH
- 5–7
- Smallest tank
- 60 litres
- Temperament
- Peaceful
- Care level
- Moderate
Tetras are small, peaceful schooling fish from soft, slightly acidic rivers. Keep them in groups of six or more in a planted tank and they'll show their best colour.
Keep a school
Tetras feel safe and behave naturally in groups of at least six, more for the smallest species. A lone tetra is stressed and pale.
Water
Most do best in soft to medium water with a pH of 6 to 7.5, plants, and subdued light. Some, like serpae tetras, nip fins; don't keep them with long-finned fish.
Food
Feed small flakes or micro-pellets and frozen or live foods such as daphnia and brine shrimp.
Further reading
General information to help you prepare, not veterinary advice. Every animal is different: ask an experienced vet about yours. Reviewed by PerfectPal on November 3, 2026.