Black Ruby Barb and Clown Knifefish Compatibility Overview
Black Ruby Barb and Clown Knifefish are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Black Ruby Barb is peaceful and Clown Knifefish is aggressive. Expect chasing and fin damage unless the tank is oversized, heavily planted, and watched closely. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Black Ruby Barb | Clown Knifefish | Verdict |
|---|---|---|---|
| Temperature | 68โ81ยฐF | 68โ82ยฐF | โ 68โ81ยฐF |
| pH Range | 5.5โ7.5 | 6.0โ8.0 | โ 6.0โ7.5 |
| Temperament | peaceful | aggressive | โ Risk |
| Adult Size | 2.2 in | 39.4 in | โ 18ร difference |
| Min. Group | 6+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
Species Profiles
Black Ruby Barb โ Pethia nigrofasciata
The Black Ruby Barb is a vibrant, active species suitable for beginners. It requires a spacious tank and a school of its own kind to thrive. Its striking colors and lively nature make it a popular choice.
โ Full Black Ruby Barb care guide
Clown Knifefish โ Chitala ornata
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.
Frequently Asked Questions
Can Black Ruby Barb live with Clown Knifefish?
Generally not recommended. Black Ruby Barb and Clown Knifefish are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Black Ruby Barb is peaceful and Clown Knifefish is aggressive. Expect chasing and fin damage unless the tank is oversized, heavily planted, and watched closely. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Black Ruby Barb and Clown Knifefish together?
A minimum of 100 gallons is recommended for keeping Black Ruby Barb and Clown Knifefish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Black Ruby Barb and Clown Knifefish?
68โ81ยฐF โ inside Black Ruby Barb's 68โ81ยฐF and Clown Knifefish's 68โ82ยฐF.
Is a Black Ruby Barb aggressive toward a Clown Knifefish?
The adult size gap creates a meaningful predation risk.
Related Compatibility Guides
Tank Size for Black Ruby Barb and Clown Knifefish
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 300 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 450 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 550 gal | Best when keeping larger schools or reducing territorial pressure. |