Compatibility Overview
Angelfish and Clown Knifefish 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 75-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Angelfish | Clown Knifefish | Verdict |
|---|---|---|---|
| Temperature | 74–84°F | 72–82°F | ✅ 74–82°F |
| pH Range | 6.0–7.5 | 6.0–7.0 | ✅ 6.0–7.0 |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 6 in | 7.9 in | ✅ Similar |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 75 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Angelfish — Pterophyllum scalare
Elegant South American cichlids with long flowing fins. Generally peaceful but territorial when breeding and will eat very small fish.
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
Frequently Asked Questions
Can Angelfish live with Clown Knifefish?
Yes, in a well-planned setup. Angelfish and Clown Knifefish 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 75-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Angelfish and Clown Knifefish together?
A minimum of 75 gallons is recommended for keeping Angelfish and Clown Knifefish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Angelfish and Clown Knifefish?
74–82°F
Is a Angelfish aggressive toward a Clown Knifefish?
Angelfish is semi and Clown Knifefish is semi. No major aggression issues are expected between these species.
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 | 80/100 |
| Ph | 100/100 |
| Temperament | 62/100 |
| Adult Size | 100/100 |
| 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. |