Compatibility Overview
Clown Knifefish and Percula Clownfish 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 | Percula Clownfish | Verdict |
|---|---|---|---|
| Temperature | 72–82°F | 75–82°F | ✅ 75–82°F |
| pH Range | 6.0–7.0 | 8.0–8.5 | ❌ No overlap |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 7.9 in | 3.1 in | ⚠️ 2.5× 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
Percula Clownfish — Aquarium species
The Percula Clownfish, also known as the False Percula, is a popular beginner fish due to its hardiness and striking coloration. These fish are best kept in a saltwater tank with a minimum size of 30 gallons and compatible tankmates. They are peaceful, non-aggressive and do well in groups with other compatible species. Regular water quality maintenance is es
Frequently Asked Questions
Can Clown Knifefish live with Percula Clownfish?
Generally not recommended. Clown Knifefish and Percula Clownfish 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 Percula Clownfish together?
A minimum of 75 gallons is recommended for keeping Clown Knifefish and Percula Clownfish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Clown Knifefish and Percula Clownfish?
75–82°F
Is a Clown Knifefish aggressive toward a Percula Clownfish?
Clown Knifefish is semi and Percula Clownfish is semi. These animals require different water types and cannot share one aquarium.
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 | 72/100 |
| 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. |