Black Ruby Barb and Cardinal Tetra Compatibility Overview
Black Ruby Barb and Cardinal Tetra can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Black Ruby Barb | Cardinal Tetra | Verdict |
|---|---|---|---|
| Temperature | 68โ81ยฐF | 73โ82ยฐF | โ 73โ81ยฐF |
| pH Range | 5.5โ7.5 | 4.5โ7.0 | โ 5.5โ7.0 |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 2.2 in | 1.5 in | โ Similar |
| Min. Group | 6+ | 6+ | See below |
| Min. Tank Size | 20 gallons (for both species) | โ | |
Compatibility Positives
Caution Points
Species Profiles
Black Ruby Barb โ Pethia nigrofasciata
The Black Ruby Barb is a vibrant, active species suitable for beginners. It requires a spacious tank and a school of its own kind to thrive. Its striking colors and lively nature make it a popular choice.
โ Full Black Ruby Barb care guide
Cardinal Tetra โ Paracheirodon axelrodi
Brilliant red-and-blue schooling fish from the Rio Negro. Prefers soft, acidic, warm water โ a natural companion for discus.
Frequently Asked Questions
Can Black Ruby Barb live with Cardinal Tetra?
Yes, in a well-planned setup. Black Ruby Barb and Cardinal Tetra can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Black Ruby Barb and Cardinal Tetra together?
A minimum of 20 gallons is recommended for keeping Black Ruby Barb and Cardinal Tetra together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Black Ruby Barb and Cardinal Tetra?
73โ81ยฐF โ inside Black Ruby Barb's 68โ81ยฐF and Cardinal Tetra's 73โ82ยฐF.
Is a Black Ruby Barb aggressive toward a Cardinal Tetra?
Black Ruby Barb is peaceful and Cardinal Tetra is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Black Ruby Barb and Cardinal Tetra
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 20 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 29 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 55 gal | Best when keeping larger schools or reducing territorial pressure. |