Compatibility Overview
Koi and Three Spot Gourami 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 | Koi | Three Spot Gourami | Verdict |
|---|---|---|---|
| Temperature | 50–75°F | 73–81°F | ⚠️ 73–75°F (narrow) |
| pH Range | 7.0–8.5 | 6.5–7.5 | ⚠️ 7.0–7.5 (narrow) |
| Temperament | peaceful | aggressive | ❌ Risk |
| Adult Size | 24 in | 2.4 in | ❌ 10× difference |
| Min. Group | 2+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
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.
Three Spot Gourami — Aquarium species
The Three Spot Gourami is a peaceful and attractive addition to freshwater tanks. They are known for their vibrant coloration and peaceful demeanor. With their flowing tails and distinctive body spots, they add visual interest to the aquarium. Providing a well-planted tank with hiding spots is crucial for their well-being. As a beginner-friendly fish, they a
Frequently Asked Questions
Can Koi live with Three Spot Gourami?
Generally not recommended. Koi and Three Spot Gourami 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 Koi and Three Spot Gourami together?
A minimum of 100 gallons is recommended for keeping Koi and Three Spot Gourami together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Koi and Three Spot Gourami?
73–75°F (narrow)
Is a Koi aggressive toward a Three Spot Gourami?
Koi is peaceful and Three Spot Gourami is aggressive. 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 | 25/100 |
| Ph | 50/100 |
| Temperament | 30/100 |
| 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. |