Congo Tetra and Pajama Cardinalfish Compatibility Overview
Congo 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: Congo Tetra wants 6.0โ7.5 and Pajama Cardinalfish wants 8.1โ8.4. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Congo Tetra | Pajama Cardinalfish | Verdict |
|---|---|---|---|
| Temperature | 73โ82ยฐF | 72โ82ยฐF | โ 73โ82ยฐF |
| pH Range | 6.0โ7.5 | 8.1โ8.4 | โ No overlap |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 3.1 in | 3.5 in | โ Similar |
| Min. Group | 6+ | 3+ | See below |
| Min. Tank Size | 55 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
Species Profiles
Congo Tetra โ Phenacogrammus interruptus
The Congo Tetra is a vibrant and active fish that thrives in a well-maintained freshwater aquarium. With its striking coloration and peaceful nature, it's a great addition to any community tank. This species is best kept in groups and requires a spacious tank with plenty of swimming space.
โ Full Congo 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 Congo Tetra live with Pajama Cardinalfish?
Generally not recommended. Congo 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: Congo Tetra wants 6.0โ7.5 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 Congo Tetra and Pajama Cardinalfish together?
A minimum of 55 gallons is recommended for keeping Congo Tetra and Pajama Cardinalfish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Congo Tetra and Pajama Cardinalfish?
73โ82ยฐF โ inside Congo Tetra's 73โ82ยฐF and Pajama Cardinalfish's 72โ82ยฐF.
Is a Congo Tetra aggressive toward a Pajama Cardinalfish?
Congo Tetra is peaceful and Pajama Cardinalfish is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Congo 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. |