Compatibility Overview
Discus and Royal Gramma 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 | Royal Gramma | Verdict |
|---|---|---|---|
| Temperature | 82–88°F | 73–81°F | ❌ No overlap |
| pH Range | 5.0–7.0 | 8.0–8.5 | ❌ No overlap |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 8 in | 1.6 in | ❌ 5× 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.
Royal Gramma — Aquarium species
The Royal Gramma, known for its vibrant blue coloration, is a popular saltwater fish among beginners and experienced aquarists alike. It requires a well-maintained tank with plenty of swimming space and a moderate current. With a peaceful temperament and a relatively easy care routine, the Royal Gramma can be a great addition to a community tank. Its delicat
Frequently Asked Questions
Can Discus live with Royal Gramma?
Generally not recommended. Discus and Royal Gramma 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 Royal Gramma together?
A minimum of 100 gallons is recommended for keeping Discus and Royal Gramma together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Discus and Royal Gramma?
No overlap
Is a Discus aggressive toward a Royal Gramma?
Discus is semi and Royal Gramma is semi. These animals require different water types and cannot share one aquarium.
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 | 0/100 |
| Temperament | 62/100 |
| 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 | 220 gal | Best when keeping larger schools or reducing territorial pressure. |