Cardinal Tetra and Pajama Cardinalfish Compatibility Overview
Cardinal Tetra and Pajama Cardinalfish are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. Their pH ranges do not meet: Cardinal Tetra wants 4.5โ7.0 and Pajama Cardinalfish wants 8.1โ8.4. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Cardinal Tetra | Pajama Cardinalfish | Verdict |
|---|---|---|---|
| Temperature | 73โ82ยฐF | 72โ82ยฐF | โ 73โ82ยฐF |
| pH Range | 4.5โ7.0 | 8.1โ8.4 | โ No overlap |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 1.5 in | 3.5 in | โ ๏ธ 2.3ร difference |
| Min. Group | 6+ | 3+ | See below |
| Min. Tank Size | 55 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
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
Pajama Cardinalfish โ Sphaeramia nematoptera
The Pajama Cardinalfish is a popular, beginner-friendly fish that can add a splash of color to your aquarium. They are generally peaceful and can be kept in a community tank. With moderate activity levels and a preference for undisturbed swimming spaces, they require a well-maintained water quality and a spacious tank.
Frequently Asked Questions
Can Cardinal Tetra live with Pajama Cardinalfish?
Generally not recommended. Cardinal Tetra and Pajama Cardinalfish are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. Their pH ranges do not meet: Cardinal Tetra wants 4.5โ7.0 and Pajama Cardinalfish wants 8.1โ8.4. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Cardinal Tetra and Pajama Cardinalfish together?
A minimum of 55 gallons is recommended for keeping Cardinal Tetra and Pajama Cardinalfish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Pajama Cardinalfish?
73โ82ยฐF โ inside Cardinal Tetra's 73โ82ยฐF and Pajama Cardinalfish's 72โ82ยฐF.
Is a Cardinal Tetra aggressive toward a Pajama Cardinalfish?
Cardinal Tetra is peaceful and Pajama Cardinalfish is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Cardinal Tetra and Pajama Cardinalfish
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 55 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 75 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 125 gal | Best when keeping larger schools or reducing territorial pressure. |