Compatibility Overview
Cardinal Tetra and Platy 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 | Platy | Verdict |
|---|---|---|---|
| Temperature | 73–82°F | 65–80°F | ✅ 73–80°F |
| pH Range | 4.5–7.0 | 7.0–8.5 | ⚠️ 7.0–7.0 (narrow) |
| Temperament | peaceful | peaceful | ✅ Compatible |
| Adult Size | 1.5 in | 2.5 in | ✅ Similar |
| Min. Group | 6+ | 3+ | 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
Platy — Xiphophorus maculatus
Hardy livebearers that are among the easiest fish to keep. Peaceful with virtually all community species. Prolific breeders.
Frequently Asked Questions
Can Cardinal Tetra live with Platy?
Yes, in a well-planned setup. Cardinal Tetra and Platy 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 Platy together?
A minimum of 40 gallons is recommended for keeping Cardinal Tetra and Platy together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Platy?
73–80°F
Is a Cardinal Tetra aggressive toward a Platy?
Cardinal Tetra is peaceful and Platy is peaceful. pH ranges barely or do not overlap: Cardinal Tetra prefers 4.5–7.0; Platy prefers 7.0–8.5.