Can Cardinal Tetra live with Ocellaris Clownfish?
These two species are usually compatible in community tanks.
Why Cardinal Tetra and Ocellaris Clownfish Work
These two species overlap in both temperature (74–80°F overlap) and pH (- overlap range). Their temperature tolerances are close enough, and neither fish pushes the pH so far outside the other's comfort zone that it creates chronic stress. The temperament match (peaceful + semi-aggressive) is low-conflict. In a 20+ gallon tank with adequate hiding spots, these two can coexist with minimal problems.
Cardinal Tetra
Paracheirodon axelrodi
| Adult Size: | 1.5" |
| Temperament: | peaceful |
| Min Tank: | 10 gal |
| Temperature: | 73-81°F |
| pH Range: | 5.0-7.0 |
Ocellaris Clownfish
Amphiprion ocellaris
| Adult Size: | 3.0" |
| Temperament: | semi-aggressive |
| Min Tank: | 20 gal |
| Temperature: | 74-80°F |
| pH Range: | 8.1-8.4 |
Water Parameter Overlap
| Parameter | Cardinal Tetra | Ocellaris Clownfish | Overlap |
|---|---|---|---|
| Temperature | 73-81°F | 74-80°F | 6°F ✓ |
| pH | 5.0-7.0 | 8.1-8.4 | No overlap ✗ |
Compatibility Breakdown
Temperament Match: peaceful + semi-aggressive. Semi-aggressive → watch territory and feeding.
Score: 80/100 (GOOD ≥80, CAUTION ≥50, RISKY <50).
🔧 Tank Setup Requirements (for Both)
- Minimum tank: 20 gallons — sized for the larger fish in the pair.
- Temperature: keep it between 74°F and 80°F.
- pH: no shared range. One species will be outside its tolerance regardless of what you set.
- Hiding spots: essential for Cardinal Tetra — caves, plants, or driftwood to retreat when feeling stressed.
- Water changes: 25% weekly minimum. Two species mean double the bioload.
🔧 Tank Stocking Calculator
Enter tank size to calculate safe stocking levels:
Recommended Equipment
Based on tank size 20+ gallons:
Marine pellet food for clownfish
Explore Related Checks
See what else works with these fish:
⚠️ Common Reasons This Pairing Fails in Practice
- Overcrowding: Even compatible species fail in tanks that are too small. Double the species means double the bioload — 25% weekly water changes are the minimum.
- Inadequate acclimation: Adding both species on the same day without quarantine is a common mistake. Always drip-acclimate new arrivals and quarantine for 2–4 weeks.
Tools & Resources
Accuracy note: This tool uses expert rules + FishBase.org data. Individual fish behavior varies — a peaceful individual Cardinal Tetra may act differently from its species average. Always observe, quarantine new arrivals for 2-4 weeks, and avoid overcrowding. If a pairing says CAUTION, start with a smaller group and a lid.