Compatibility Overview
Clown Knifefish and Pea Puffer are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
| Factor | Clown Knifefish | Pea Puffer | Verdict |
|---|---|---|---|
| Temperature | 72–82°F | 74–82°F | ✅ 74–82°F |
| pH Range | 6.0–7.0 | 7.0–8.0 | ⚠️ 7.0–7.0 (narrow) |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 7.9 in | 1 in | ❌ 8× difference |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 75 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Clown Knifefish — Aquarium species
The Clown Knifefish is a unique and visually striking species known for its slender body and distinctive coloration. It is a solitary fish that requires a spacious tank to thrive. With a moderate activity level and low aggression, it can be a suitable addition to a community tank with similarly peaceful species. Regular water changes and a balanced diet are
→ Full Clown Knifefish 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 Clown Knifefish live with Pea Puffer?
Generally not recommended. Clown Knifefish and Pea Puffer are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
What tank size do I need for Clown Knifefish and Pea Puffer together?
A minimum of 75 gallons is recommended for keeping Clown Knifefish and Pea Puffer together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Clown Knifefish and Pea Puffer?
74–82°F
Is a Clown Knifefish aggressive toward a Pea Puffer?
Clown Knifefish is semi and Pea Puffer is semi. The adult size gap creates a meaningful predation risk.
Related Compatibility Guides
Compatibility score breakdown
The overall score is weighted across water chemistry, behavior, adult size, swimming zone, and social needs. A score is a planning aid—not a guarantee for individual fish.
| Factor | Score |
|---|---|
| Temperature | 100/100 |
| Ph | 0/100 |
| Temperament | 62/100 |
| Adult Size | 8/100 |
| Swim Zone | 68/100 |
| Social Needs | 92/100 |
Tank size scenarios
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 75 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 125 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 150 gal | Best when keeping larger schools or reducing territorial pressure. |