Compatibility Overview
Julii Cory and Silver Arowana 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 | Julii Cory | Silver Arowana | Verdict |
|---|---|---|---|
| Temperature | 72–79°F | 72–86°F | ✅ 72–79°F |
| pH Range | 6.0–7.0 | 6.0–7.5 | ✅ 6.0–7.0 |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 1.2 in | 19.7 in | ❌ 16× difference |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
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
Silver Arowana — Aquarium species
The Silver Arowana is a majestic and unique fish known for its striking appearance and size. It is a large, predatory fish that requires a spacious tank and specific water conditions. While not a community fish, it can be kept with compatible, larger species. They are sensitive to stress and require careful water quality management.
Frequently Asked Questions
Can Julii Cory live with Silver Arowana?
Generally not recommended. Julii Cory and Silver Arowana 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 Julii Cory and Silver Arowana together?
A minimum of 100 gallons is recommended for keeping Julii Cory and Silver Arowana together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Julii Cory and Silver Arowana?
72–79°F
Is a Julii Cory aggressive toward a Silver Arowana?
Julii Cory is semi and Silver Arowana is semi. The adult size gap creates a meaningful predation risk.
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 | 100/100 |
| Temperament | 62/100 |
| Adult Size | 8/100 |
| 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 | 528 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 750 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 950 gal | Best when keeping larger schools or reducing territorial pressure. |