Compatibility Overview
Cardinal Tetra and Pea Puffer can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 30 gallons), dense planting, and close monitoring are essential.
| Factor | Cardinal Tetra | Pea Puffer | Verdict |
|---|---|---|---|
| Temperature | 73–82°F | 74–82°F | ✅ 74–82°F |
| pH Range | 4.5–7.0 | 7.0–8.0 | ⚠️ 7.0–7.0 (narrow) |
| Temperament | peaceful | semi | ⚠️ Monitor |
| Adult Size | 1.5 in | 1 in | ✅ Similar |
| Min. Group | 6+ | 1+ | See below |
| Min. Tank Size | 30 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
Pea Puffer — Carinotetraodon travancoricus
World's smallest pufferfish — intensely territorial and nippy despite tiny size. Will attack fins and eat shrimp and snails.
Frequently Asked Questions
Can Cardinal Tetra live with Pea Puffer?
With significant caution and a larger tank. Cardinal Tetra and Pea Puffer can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 30 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Cardinal Tetra and Pea Puffer together?
A minimum of 30 gallons is recommended for keeping Cardinal Tetra and Pea Puffer together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Pea Puffer?
74–82°F
Is a Cardinal Tetra aggressive toward a Pea Puffer?
Cardinal Tetra is peaceful and Pea Puffer is semi. pH ranges barely or do not overlap: Cardinal Tetra prefers 4.5–7.0; Pea Puffer prefers 7.0–8.0.