Compatibility Overview
Firefish Goby and Pajama Cardinalfish can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges, and neither poses a major aggression risk to the other. A minimum 15-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Firefish Goby | Pajama Cardinalfish | Verdict |
|---|---|---|---|
| Temperature | 72–81°F | 72–82°F | ✅ 72–81°F |
| pH Range | 8.1–8.4 | 8.0–8.3 | ⚠️ 8.1–8.3 (narrow) |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 1.2 in | 1.6 in | ✅ Similar |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 15 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Firefish Goby — Aquarium species
The Firefish Goby is a popular choice for saltwater aquariums due to its vibrant colors and peaceful nature. These goby fish thrive in well-maintained tanks with plenty of live rock for them to explore. They are best kept in pairs or small groups and can be a great addition to a community tank with compatible species. It's important to provide them with a sp
→ Full Firefish Goby care guide
Pajama Cardinalfish — Aquarium species
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 Firefish Goby live with Pajama Cardinalfish?
Yes, in a well-planned setup. Firefish Goby and Pajama Cardinalfish can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges, and neither poses a major aggression risk to the other. A minimum 15-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Firefish Goby and Pajama Cardinalfish together?
A minimum of 15 gallons is recommended for keeping Firefish Goby and Pajama Cardinalfish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Firefish Goby and Pajama Cardinalfish?
72–81°F
Is a Firefish Goby aggressive toward a Pajama Cardinalfish?
Firefish Goby is semi and Pajama Cardinalfish is semi. No major aggression issues are expected between these species.
Related Compatibility Guides
Compatibility score breakdown
The overall score is weighted across water chemistry, behavior, adult size, swimming zone, and social needs. A score is a planning aid—not a guarantee for individual fish.
| Factor | Score |
|---|---|
| Temperature | 100/100 |
| Ph | 67/100 |
| Temperament | 62/100 |
| Adult Size | 100/100 |
| Swim Zone | 92/100 |
| Social Needs | 92/100 |
Tank size scenarios
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 16 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 | 40 gal | Best when keeping larger schools or reducing territorial pressure. |