The cardinal tetra (Paracheirodon axelrodi) is a peaceful fish that grows to about 2 inches and spends its time in mid-water. Keep at least 6 together, in a tank of 20 gallons or more, at 73–81°F and pH 4.5–7.
20 galsmallest tank
2″adult size
73–81°Ftemperature
4.5–7pH
6+group size
Peacefultemperament
Good tankmates
Avoid
- ✕White cloud mountain minnow: Cardinal tetra and White cloud mountain minnow need different temperatures (73–81°F vs 60–72°F).
- ✕Rosy barb: Cardinal tetra and Rosy barb need different temperatures (73–81°F vs 64–72°F).
- ✕Molly: Cardinal tetra and Molly prefer different water (pH 4.5–7 vs 7.5–8.5).
- ✕Paradise fish: Paradise fish is aggressive and best kept alone.
- ✕Angelfish: Angelfish grows big enough to eat Cardinal tetra.
- ✕Convict cichlid: Convict cichlid is aggressive and best kept alone.
- ✕Oscar: Oscar is aggressive and best kept alone.
- ✕Fancy goldfish: Cardinal tetra and Fancy goldfish need different temperatures (73–81°F vs 65–72°F).
From TankCoach's own species data: common hobby guidance for adults, rounded. Individual fish vary. Not veterinary advice.