Can Cardinal Tetra live with Guppy?
These two species are usually compatible in community tanks.
Why Cardinal Tetra and Guppy Work
These two species overlap in both temperature (73–81°F overlap) and pH (6.8-7.0 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 + peaceful) is low-conflict. In a 10+ 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 |
Guppy
Poecilia reticulata
| Adult Size: | 2.0" |
| Temperament: | peaceful |
| Min Tank: | 10 gal |
| Temperature: | 72-82°F |
| pH Range: | 6.8-7.8 |
Water Parameter Overlap
| Parameter | Cardinal Tetra | Guppy | Overlap |
|---|---|---|---|
| Temperature | 73-81°F | 72-82°F | 8°F ✓ |
| pH | 5.0-7.0 | 6.8-7.8 | 0.2 ✓ |
Compatibility Breakdown
Temperament Match: peaceful + peaceful. Both peaceful → minimal conflict.
Score: 114.0/100 (GOOD ≥80, CAUTION ≥50, RISKY <50).
🔧 Tank Setup Requirements (for Both)
- Minimum tank: 10 gallons — sized for the larger fish in the pair.
- Temperature: keep it between 73°F and 81°F.
- pH: maintain 6.8 – 7.0.
- 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 10+ gallons:
Small floating pellets perfect for tetras
Explore Related Checks
See what else works with these fish:
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.