Cardinal Tetra and Guppy Compatibility Overview
Cardinal Tetra and Guppy can potentially coexist, but the combination requires careful attention. Their usable pH overlap is narrow and requires stable, tested water. A larger tank (minimum 20 gallons), dense planting, and close monitoring are essential.
| Factor | Cardinal Tetra | Guppy | Verdict |
|---|---|---|---|
| Temperature | 73โ82ยฐF | 72โ82ยฐF | โ 73โ82ยฐF |
| pH Range | 4.5โ7.0 | 6.8โ8.5 | โ ๏ธ 6.8โ7.0 (narrow) |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 1.5 in | 2.5 in | โ Similar |
| Min. Group | 6+ | 3+ | See below |
| Min. Tank Size | 20 gallons (for both species) | โ | |
Compatibility Positives
Caution Points
Species Profiles
Cardinal Tetra โ Paracheirodon axelrodi
Brilliant red-and-blue schooling fish from the Rio Negro. Prefers soft, acidic, warm water โ a natural companion for discus.
โ Full Cardinal Tetra care guide
Guppy โ Poecilia reticulata
Hardy and colourful livebearers. Males' long flowing tails make them targets for fin-nipping species. Very prolific breeders.
Frequently Asked Questions
Can Cardinal Tetra live with Guppy?
With significant caution and a larger tank. Cardinal Tetra and Guppy can potentially coexist, but the combination requires careful attention. Their usable pH overlap is narrow and requires stable, tested water. A larger tank (minimum 20 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Cardinal Tetra and Guppy together?
A minimum of 20 gallons is recommended for keeping Cardinal Tetra and Guppy together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Guppy?
73โ82ยฐF โ inside Cardinal Tetra's 73โ82ยฐF and Guppy's 72โ82ยฐF.
Is a Cardinal Tetra aggressive toward a Guppy?
Cardinal Tetra is peaceful and Guppy is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Cardinal Tetra and Guppy
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 20 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 29 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 55 gal | Best when keeping larger schools or reducing territorial pressure. |