Compatibility Overview
Cardinal Tetra and Moonlight Gourami 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 40-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Cardinal Tetra | Moonlight Gourami | Verdict |
|---|---|---|---|
| Temperature | 73–82°F | 72–82°F | ✅ 73–82°F |
| pH Range | 4.5–7.0 | 6.5–7.5 | ⚠️ 6.5–7.0 (narrow) |
| Temperament | peaceful | semi | ⚠️ Monitor |
| Adult Size | 1.5 in | 2.0 in | ✅ Similar |
| Min. Group | 6+ | 1+ | See below |
| Min. Tank Size | 40 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
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
Moonlight Gourami — Aquarium species
The Moonlight Gourami is a beautiful freshwater fish known for its silvery blue color and red eyes. It is a peaceful community fish suitable for beginners and can thrive in a well-maintained aquarium. These fish are sensitive to water quality and require a spacious tank with plenty of swimming space. They are not known to school and prefer to have their terr
Frequently Asked Questions
Can Cardinal Tetra live with Moonlight Gourami?
Yes, in a well-planned setup. Cardinal Tetra and Moonlight Gourami 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 40-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Cardinal Tetra and Moonlight Gourami together?
A minimum of 40 gallons is recommended for keeping Cardinal Tetra and Moonlight Gourami together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Moonlight Gourami?
73–82°F
Is a Cardinal Tetra aggressive toward a Moonlight Gourami?
Cardinal Tetra is peaceful and Moonlight Gourami 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 | 50/100 |
| Temperament | 75/100 |
| Adult Size | 100/100 |
| Swim Zone | 68/100 |
| 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 | 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. |