Compatibility Overview
Cardinal Tetra and Silver Arowana 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 | Silver Arowana | Verdict |
|---|---|---|---|
| Temperature | 73–82°F | 72–86°F | ✅ 73–82°F |
| pH Range | 4.5–7.0 | 6.0–7.5 | ✅ 6.0–7.0 |
| Temperament | peaceful | semi | ⚠️ Monitor |
| Adult Size | 1.5 in | 19.7 in | ❌ 13× difference |
| Min. Group | 6+ | 1+ | See below |
| Min. Tank Size | 100 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
Silver Arowana — Aquarium species
The Silver Arowana is a majestic and unique fish known for its striking appearance and size. It is a large, predatory fish that requires a spacious tank and specific water conditions. While not a community fish, it can be kept with compatible, larger species. They are sensitive to stress and require careful water quality management.
Frequently Asked Questions
Can Cardinal Tetra live with Silver Arowana?
Generally not recommended. Cardinal Tetra and Silver Arowana 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 Silver Arowana together?
A minimum of 100 gallons is recommended for keeping Cardinal Tetra and Silver Arowana together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Silver Arowana?
73–82°F
Is a Cardinal Tetra aggressive toward a Silver Arowana?
Cardinal Tetra is peaceful and Silver Arowana is semi. The adult size gap creates a meaningful predation risk.
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 | 75/100 |
| Adult Size | 8/100 |
| 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 | 528 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 750 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 950 gal | Best when keeping larger schools or reducing territorial pressure. |