Compatibility Overview
Moonlight Gourami and Oscar 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 | Moonlight Gourami | Oscar | Verdict |
|---|---|---|---|
| Temperature | 72–82°F | 74–81°F | ✅ 74–81°F |
| pH Range | 6.5–7.5 | 6.0–8.0 | ✅ 6.5–7.5 |
| Temperament | semi | aggressive | ❌ Risk |
| Adult Size | 2.0 in | 14 in | ❌ 7× difference |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Moonlight Gourami — Aquarium species
The Moonlight Gourami is a beautiful freshwater fish known for its silvery blue color and red eyes. It is a peaceful community fish suitable for beginners and can thrive in a well-maintained aquarium. These fish are sensitive to water quality and require a spacious tank with plenty of swimming space. They are not known to school and prefer to have their terr
→ Full Moonlight Gourami care guide
Oscar — Astronotus ocellatus
Intelligent but aggressive cichlids that will eat any fish small enough to fit in their mouth. Require large tanks (75+ gallons) and robust tank mates.
Frequently Asked Questions
Can Moonlight Gourami live with Oscar?
Generally not recommended. Moonlight Gourami and Oscar 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 Moonlight Gourami and Oscar together?
A minimum of 100 gallons is recommended for keeping Moonlight Gourami and Oscar together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Moonlight Gourami and Oscar?
74–81°F
Is a Moonlight Gourami aggressive toward a Oscar?
Moonlight Gourami is semi and Oscar is aggressive. 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 | 25/100 |
| 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. |