Cardinal Tetra and Rosy Barb Compatibility Overview
Cardinal Tetra and Rosy Barb can potentially coexist, but the combination requires careful attention. Their ranges meet only at 73โ75ยฐF, which leaves no margin for a heater drifting or a warm room. Their pH ranges overlap only partly, so aim for the shared band and keep it steady. A larger tank (minimum 75 gallons), dense planting, and close monitoring are essential.
| Factor | Cardinal Tetra | Rosy Barb | Verdict |
|---|---|---|---|
| Temperature | 73โ82ยฐF | 61โ75ยฐF | โ ๏ธ 73โ75ยฐF (narrow) |
| pH Range | 4.5โ7.0 | 6.0โ8.0 | โ 6.0โ7.0 |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 1.5 in | 3.9 in | โ ๏ธ 2.6ร difference |
| Min. Group | 6+ | 8+ | See below |
| Min. Tank Size | 75 gallons (for both species) | โ | |
Compatibility Positives
Caution Points
Species Profiles
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.
โ Full Cardinal Tetra care guide
Rosy Barb โ Pethia conchonius
The Rosy Barb is a popular freshwater fish known for its vibrant coloration and peaceful nature. It is well-suited for community tanks with other non-aggressive species. They require a well-maintained environment and can be sensitive to water quality fluctuations. With proper care, they can thrive and add a splash of color to your aquarium.
Frequently Asked Questions
Can Cardinal Tetra live with Rosy Barb?
With significant caution and a larger tank. Cardinal Tetra and Rosy Barb can potentially coexist, but the combination requires careful attention. Their ranges meet only at 73โ75ยฐF, which leaves no margin for a heater drifting or a warm room. Their pH ranges overlap only partly, so aim for the shared band and keep it steady. A larger tank (minimum 75 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Cardinal Tetra and Rosy Barb together?
A minimum of 75 gallons is recommended for keeping Cardinal Tetra and Rosy Barb together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Rosy Barb?
73โ75ยฐF (narrow) โ inside Cardinal Tetra's 73โ82ยฐF and Rosy Barb's 61โ75ยฐF.
Is a Cardinal Tetra aggressive toward a Rosy Barb?
Cardinal Tetra is peaceful and Rosy Barb is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Cardinal Tetra and Rosy Barb
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 75 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 125 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 150 gal | Best when keeping larger schools or reducing territorial pressure. |