Compatibility Overview
Glass Catfish 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 | Glass Catfish | 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 | 3.9 in | 14 in | ⚠️ 3.6× difference |
| Min. Group | 6+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Glass Catfish — Aquarium species
The Glass Catfish, Kryptopterus vitreolus, is a popular freshwater aquarium fish known for its unique, translucent body and iridescent scales. It is a peaceful species that thrives in groups and is suitable for beginners due to its hardy nature. These catfish are bottom-dwellers and require a well-decorated tank with plenty of swimming space. They are sensit
→ Full Glass Catfish 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 Glass Catfish live with Oscar?
Generally not recommended. Glass Catfish 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 Glass Catfish and Oscar together?
A minimum of 100 gallons is recommended for keeping Glass Catfish and Oscar together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Glass Catfish and Oscar?
74–81°F
Is a Glass Catfish aggressive toward a Oscar?
Glass Catfish 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 | 38/100 |
| 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 | 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 | 220 gal | Best when keeping larger schools or reducing territorial pressure. |