Compatibility Overview
Black Ruby Barb and Julii Cory can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 40 gallons), dense planting, and close monitoring are essential.
| Factor | Black Ruby Barb | Julii Cory | Verdict |
|---|---|---|---|
| Temperature | 72–79°F | 72–79°F | ✅ 72–79°F |
| pH Range | 6.5–7.5 | 6.0–7.0 | ⚠️ 6.5–7.0 (narrow) |
| Temperament | aggressive | semi | ❌ Risk |
| Adult Size | 1.6 in | 1.2 in | ✅ Similar |
| Min. Group | 6+ | 1+ | See below |
| Min. Tank Size | 40 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Black Ruby Barb — Aquarium species
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.
→ Full Black Ruby Barb care guide
Julii Cory — Aquarium species
The Julii Cory is a popular, peaceful bottom-dweller that thrives in community tanks. With a lifespan of up to 5 years, they are suitable for beginners and experienced aquarists alike. These fish are known for their dark brown coloration with distinctive white spots and a slender, flat body shape. They are moderately active and prefer a well-planted tank wit
Frequently Asked Questions
Can Black Ruby Barb live with Julii Cory?
With significant caution and a larger tank. Black Ruby Barb and Julii Cory can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 40 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Black Ruby Barb and Julii Cory together?
A minimum of 40 gallons is recommended for keeping Black Ruby Barb and Julii Cory together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Black Ruby Barb and Julii Cory?
72–79°F
Is a Black Ruby Barb aggressive toward a Julii Cory?
Black Ruby Barb is aggressive and Julii Cory 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 | 100/100 |
| Ph | 50/100 |
| Temperament | 25/100 |
| Adult Size | 100/100 |
| Swim Zone | 92/100 |
| 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 | 40 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 55 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 90 gal | Best when keeping larger schools or reducing territorial pressure. |