Compatibility Overview
Discus and Giant 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 | Giant Danio | 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 | 2.0 in | ❌ 4× difference |
| Min. Group | 5+ | 1+ | 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.
Giant Danio — Aquarium species
The Giant Danio is a vibrant and peaceful addition to the freshwater aquarium. Known for its striking red and blue colors, it is a popular choice for beginners and experienced aquarists alike. These fish are relatively easy to care for and can thrive in a well-maintained tank. They are best kept in groups of at least six to ensure their well-being and displa
Frequently Asked Questions
Can Discus live with Giant Danio?
Generally not recommended. Discus and Giant 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 Giant Danio together?
A minimum of 100 gallons is recommended for keeping Discus and Giant Danio together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Discus and Giant Danio?
82–82°F (narrow)
Is a Discus aggressive toward a Giant Danio?
Discus is semi and Giant Danio is semi. 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 | 50/100 |
| Temperament | 62/100 |
| Adult Size | 38/100 |
| 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 | 220 gal | Best when keeping larger schools or reducing territorial pressure. |