๐Ÿ  Fish Compatibility Guide

Can Black Ruby Barb and Threadfin Rainbowfish Live Together?

Updated September 23, 2026 ยท FishCare AI Editorial Team

โœ… Compatible โ€” Compatibility Score: 89/100
89/100 โ€” Compatible

Black Ruby Barb and Threadfin Rainbowfish Compatibility Overview

Black Ruby Barb and Threadfin Rainbowfish can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.

Compatibility factors for Black Ruby Barb and Threadfin Rainbowfish
FactorBlack Ruby BarbThreadfin RainbowfishVerdict
Temperature68โ€“81ยฐF72โ€“86ยฐFโœ… 72โ€“81ยฐF
pH Range5.5โ€“7.55.0โ€“8.0โœ… 5.5โ€“7.5
Temperamentpeacefulpeacefulโœ… Compatible
Adult Size2.2 in1.6 inโœ… Similar
Min. Group6+6+See below
Min. Tank Size20 gallons (for both species)โ€”

Compatibility Positives

A stable shared temperature range is available.
Their pH requirements overlap.
Temperament risk is relatively low when normal group sizes are maintained.

Caution Points

No major compatibility issues identified for this pair.

Species Profiles

Black Ruby Barb โ€” Pethia nigrofasciata

Black Ruby Barb and Threadfin Rainbowfish compatibility โ€” Black Ruby Barb

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

Threadfin Rainbowfish โ€” Iriatherina werneri

Black Ruby Barb and Threadfin Rainbowfish compatibility โ€” Threadfin Rainbowfish

The Threadfin Rainbowfish is a popular choice for freshwater aquariums due to its vibrant colors and peaceful nature. It requires a well-maintained tank with plenty of swimming space and a moderate water flow. These fish are not known to be aggressive and can be kept in community tanks with other peaceful species.

โ†’ Full Threadfin Rainbowfish care guide

Frequently Asked Questions

Can Black Ruby Barb live with Threadfin Rainbowfish?

Yes, in a well-planned setup. Black Ruby Barb and Threadfin Rainbowfish can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.

What tank size do I need for Black Ruby Barb and Threadfin Rainbowfish together?

A minimum of 20 gallons is recommended for keeping Black Ruby Barb and Threadfin Rainbowfish together. A larger tank improves water stability and reduces territorial conflict.

What temperature suits both Black Ruby Barb and Threadfin Rainbowfish?

72โ€“81ยฐF โ€” inside Black Ruby Barb's 68โ€“81ยฐF and Threadfin Rainbowfish's 72โ€“86ยฐF.

Is a Black Ruby Barb aggressive toward a Threadfin Rainbowfish?

Black Ruby Barb is peaceful and Threadfin Rainbowfish is peaceful. No major aggression issues are expected between these species.

Related Compatibility Guides

Tank Size for Black Ruby Barb and Threadfin Rainbowfish

Use the scenario that matches the actual group sizes and temperament you plan to keep.

ScenarioTankWhen it applies
Minimum viable20 galOnly for the recommended minimum groups, mature filtration, and close monitoring.
Recommended community29 galAdds territory, swimming room, and a safer buffer for behavior.
Low-conflict setup55 galBest when keeping larger schools or reducing territorial pressure.