Cardinal Tetra
Paracheirodon axelrodi
Minimum Tank
15 Gallons
Adult Size
2 inches
Temperature
73-81°F (23-27°C)
pH Range
5.5-7.0
Lifespan
5 years
School Size
8+ fish
About Cardinal Tetra
The cardinal tetra is a jewel-like freshwater fish from the blackwater tributaries of the Rio Negro and Orinoco basins in South America. Often confused with the neon tetra, the cardinal is distinguished by its red stripe extending the full length of its body, from head to tail, rather than just the posterior half. In the wild, cardinal tetras inhabit extremely soft, acidic waters stained dark brown by tannins from decomposing leaves. They are one of the most commercially important ornamental fish species, with millions exported from Brazil and Colombia annually. A large school of cardinal tetras in a darkwater aquarium setup is widely considered one of the most spectacular displays in the freshwater hobby.
Care Requirements
Tank Setup
- • Minimum 15-gallon tank required
- • Temperature: 73-81°F (23-27°C)
- • pH: 5.5 - 7.0
- • Category: Tetra
Diet & Feeding
- • Diet type: Omnivore
- • Feed 1-2 times daily
- • Varied diet recommended
Tank Mate Compatibility
Compatible With
Avoid Keeping With
Care Tips
Expert Tips
Cardinal tetras are more sensitive to water conditions than their neon tetra cousins and do best in soft, acidic water with a pH of 5.0-7.0. Add Indian almond leaves or alder cones to provide beneficial tannins that mimic their natural habitat and have antifungal properties. Keep them in schools of at least ten for the most natural behavior and stunning visual impact. They prefer dim lighting and a dark substrate, which showcases their iridescent colors beautifully. Avoid keeping them with large or aggressive fish. Feed a varied diet of quality micro-pellets, crushed flakes, and frozen foods like daphnia and baby brine shrimp.
Quick Facts
57L
Min Tank (15gal)
5cm
Adult Size (2")
5yr
Lifespan
8+
Min School
Build Your Perfect Community Tank
Find compatible tankmates for your Cardinal Tetra
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Tank Mates for Cardinal Tetra
Species from our database with overlapping water parameters, compatible temperaments and a realistic shared tank size.
Otocinclus
Otocinclus sp.
moderate · 10+ gal
Julii Corydoras
Corydoras julii
easy · 15+ gal
Phoenix Rasbora
Boraras merah
moderate · 5+ gal
Chili Rasbora
Boraras brigittae
moderate · 5+ gal
Similar Care Level
Other moderate-care species that suit a comparable setup.
Frequently Asked Questions
What size tank does a Cardinal Tetra need?
A Cardinal Tetra needs a minimum tank size of 15 gallons (57 litres). They should be kept in schools of at least 8.
What water parameters does a Cardinal Tetra need?
Cardinal Tetra thrive in water between 73-81°F (23-27°C) with a pH of 5.5-7.0.
Are Cardinal Tetra easy to care for?
Cardinal Tetra are considered moderate to care for. They are peaceful fish with a lifespan of about 5 years.
How big do Cardinal Tetra get and what do they eat?
Cardinal Tetra reach about 2 inches and are omnivores. Cardinal tetras are more sensitive to water conditions than their neon tetra cousins and do best in soft, acidic water with a pH of 5.0-7.0. Add Indian almond leaves or alder cones to provide beneficial tannins that mimic their natural habitat and have antifungal properties. Keep them in schools of at least ten for the most natural behavior and stunning visual impact. They prefer dim lighting and a dark substrate, which showcases their iridescent colors beautifully. Avoid keeping them with large or aggressive fish. Feed a varied diet of quality micro-pellets, crushed flakes, and frozen foods like daphnia and baby brine shrimp.