Compatibility Overview
Angelfish and Diamond Tetra 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 | Angelfish | Diamond Tetra | Verdict |
|---|---|---|---|
| Temperature | 74–84°F | 72–82°F | ✅ 74–82°F |
| pH Range | 6.0–7.5 | 6.0–7.5 | ✅ 6.0–7.5 |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 6 in | 1.2 in | ❌ 5× difference |
| Min. Group | 1+ | 6+ | See below |
| Min. Tank Size | 75 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Angelfish — Pterophyllum scalare
Elegant South American cichlids with long flowing fins. Generally peaceful but territorial when breeding and will eat very small fish.
Diamond Tetra — Aquarium species
The Diamond Tetra is a popular freshwater fish known for its vibrant colors and peaceful nature. It is well-suited for community tanks and can thrive in a variety of water conditions. With a moderate activity level and a preference for schools, this species is a great addition to any beginner or intermediate aquarist's tank.
Frequently Asked Questions
Can Angelfish live with Diamond Tetra?
Generally not recommended. Angelfish and Diamond Tetra 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 Angelfish and Diamond Tetra together?
A minimum of 75 gallons is recommended for keeping Angelfish and Diamond Tetra together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Angelfish and Diamond Tetra?
74–82°F
Is a Angelfish aggressive toward a Diamond Tetra?
Angelfish is semi and Diamond Tetra 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 | 80/100 |
| Ph | 100/100 |
| 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 | 75 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 125 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 150 gal | Best when keeping larger schools or reducing territorial pressure. |