Compatibility Overview
Cardinal Tetra and Firefish Goby are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
| Factor | Cardinal Tetra | Firefish Goby | Verdict |
|---|---|---|---|
| Temperature | 73–82°F | 72–81°F | ✅ 73–81°F |
| pH Range | 4.5–7.0 | 8.1–8.4 | ❌ No overlap |
| Temperament | peaceful | semi | ⚠️ Monitor |
| Adult Size | 1.5 in | 1.2 in | ✅ Similar |
| Min. Group | 6+ | 1+ | See below |
| Min. Tank Size | 30 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Cardinal Tetra — Paracheirodon axelrodi
Brilliant red-and-blue schooling fish from the Rio Negro. Prefers soft, acidic, warm water — a natural companion for discus.
→ Full Cardinal Tetra care guide
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
Frequently Asked Questions
Can Cardinal Tetra live with Firefish Goby?
Generally not recommended. Cardinal Tetra and Firefish Goby are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
What tank size do I need for Cardinal Tetra and Firefish Goby together?
A minimum of 30 gallons is recommended for keeping Cardinal Tetra and Firefish Goby together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Firefish Goby?
73–81°F
Is a Cardinal Tetra aggressive toward a Firefish Goby?
Cardinal Tetra is peaceful and Firefish Goby is semi. These animals require different water types and cannot share one aquarium.
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 | 89/100 |
| Ph | 0/100 |
| Temperament | 75/100 |
| 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 | 30 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 | 75 gal | Best when keeping larger schools or reducing territorial pressure. |