Guppy and Pajama Cardinalfish Compatibility Overview
Guppy 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 usable pH overlap is narrow and requires stable, tested water. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Guppy | Pajama Cardinalfish | Verdict |
|---|---|---|---|
| Temperature | 72โ82ยฐF | 72โ82ยฐF | โ 72โ82ยฐF |
| pH Range | 6.8โ8.5 | 8.1โ8.4 | โ ๏ธ 8.1โ8.4 (narrow) |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 2.5 in | 3.5 in | โ Similar |
| Min. Group | 3+ | 3+ | See below |
| Min. Tank Size | 40 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
Species Profiles
Guppy โ Poecilia reticulata
Hardy and colourful livebearers. Males' long flowing tails make them targets for fin-nipping species. Very prolific breeders.
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 Guppy live with Pajama Cardinalfish?
Generally not recommended. Guppy 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 usable pH overlap is narrow and requires stable, tested water. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Guppy and Pajama Cardinalfish together?
A minimum of 40 gallons is recommended for keeping Guppy and Pajama Cardinalfish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Guppy and Pajama Cardinalfish?
72โ82ยฐF โ inside Guppy's 72โ82ยฐF and Pajama Cardinalfish's 72โ82ยฐF.
Is a Guppy aggressive toward a Pajama Cardinalfish?
Guppy is peaceful and Pajama Cardinalfish is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Guppy 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 | 40 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 55 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 90 gal | Best when keeping larger schools or reducing territorial pressure. |