Compatibility Overview
Discus and Glass Catfish can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 100 gallons), dense planting, and close monitoring are essential.
| Factor | Discus | Glass Catfish | Verdict |
|---|---|---|---|
| Temperature | 82–88°F | 72–82°F | ⚠️ 82–82°F (narrow) |
| pH Range | 5.0–7.0 | 6.5–7.5 | ⚠️ 6.5–7.0 (narrow) |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 8 in | 3.9 in | ⚠️ 2.1× difference |
| Min. Group | 5+ | 6+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Discus — Symphysodon spp.
The 'king of the aquarium' — beautiful but demanding. Requires very warm, soft, acidic water that excludes most community fish.
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
Frequently Asked Questions
Can Discus live with Glass Catfish?
With significant caution and a larger tank. Discus and Glass Catfish can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 100 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Discus and Glass Catfish together?
A minimum of 100 gallons is recommended for keeping Discus and Glass Catfish together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Discus and Glass Catfish?
82–82°F (narrow)
Is a Discus aggressive toward a Glass Catfish?
Discus is semi and Glass Catfish is semi. Their preferred temperature ranges have little or no safe overlap.
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 | 50/100 |
| Temperament | 62/100 |
| Adult Size | 72/100 |
| Swim Zone | 92/100 |
| Social Needs | 85/100 |
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. |