Compatibility Overview
Discus and Glowlight Danio 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 | Discus | Glowlight Danio | Verdict |
|---|---|---|---|
| Temperature | 82–88°F | 72–82°F | ⚠️ 82–82°F (narrow) |
| pH Range | 5.0–7.0 | 6.0–7.5 | ✅ 6.0–7.0 |
| Temperament | semi | aggressive | ❌ Risk |
| Adult Size | 8 in | 1.6 in | ❌ 5× difference |
| Min. Group | 5+ | 6+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Discus — Symphysodon spp.
The 'king of the aquarium' — beautiful but demanding. Requires very warm, soft, acidic water that excludes most community fish.
Glowlight Danio — Aquarium species
The Glowlight Danio is a popular freshwater fish known for its vibrant colors and active nature. They are ideal for beginners due to their hardiness and ease of care. These fish thrive in a well-maintained tank with plenty of swimming space and a school of their own kind.
Frequently Asked Questions
Can Discus live with Glowlight Danio?
Generally not recommended. Discus and Glowlight Danio 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 Discus and Glowlight Danio together?
A minimum of 100 gallons is recommended for keeping Discus and Glowlight Danio together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Discus and Glowlight Danio?
82–82°F (narrow)
Is a Discus aggressive toward a Glowlight Danio?
Discus is semi and Glowlight Danio 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 | 0/100 |
| Ph | 67/100 |
| Temperament | 25/100 |
| Adult Size | 8/100 |
| Swim Zone | 68/100 |
| 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. |