Compatibility Overview
Coral Beauty and Koi 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 | Coral Beauty | Koi | Verdict |
|---|---|---|---|
| Temperature | 75–81°F | 50–75°F | ⚠️ 75–75°F (narrow) |
| pH Range | 8.0–8.3 | 7.0–8.5 | ⚠️ 8.0–8.3 (narrow) |
| Temperament | semi | peaceful | ⚠️ Monitor |
| Adult Size | 2.4 in | 24 in | ❌ 10× difference |
| Min. Group | 1+ | 2+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Coral Beauty — Aquarium species
The Coral Beauty Angelfish is a popular choice for reef tanks due to its vibrant colors and gentle demeanor. These fish thrive in well-maintained aquariums with plenty of swimming space and hiding spots. They are generally peaceful with other compatible fish but can be sensitive to aggressive tankmates. A diet rich in variety is essential for their health.
→ Full Coral Beauty care guide
Koi — Cyprinus rubrofuscus
Large pond fish that require hundreds of gallons and cool water. Will eat any fish small enough to fit in their mouth.
Frequently Asked Questions
Can Coral Beauty live with Koi?
Generally not recommended. Coral Beauty and Koi 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 Coral Beauty and Koi together?
A minimum of 100 gallons is recommended for keeping Coral Beauty and Koi together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Coral Beauty and Koi?
75–75°F (narrow)
Is a Coral Beauty aggressive toward a Koi?
Coral Beauty is semi and Koi is peaceful. These animals require different water types and cannot share one aquarium.
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 | 0/100 |
| Ph | 100/100 |
| Temperament | 75/100 |
| Adult Size | 8/100 |
| 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 | 100 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 150 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 180 gal | Best when keeping larger schools or reducing territorial pressure. |