Compatibility Overview
Fire Eel and Silver Dollar 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 | Fire Eel | Silver Dollar | Verdict |
|---|---|---|---|
| Temperature | 75–82°F | 72–79°F | ✅ 75–79°F |
| pH Range | 6.0–7.0 | 6.0–7.0 | ✅ 6.0–7.0 |
| Temperament | aggressive | semi | ❌ Risk |
| Adult Size | 19.7 in | 7.9 in | ⚠️ 2.5× difference |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Fire Eel — Aquarium species
The Fire Eel is a stunning, red-bottomed species that requires a spacious tank. They are peaceful bottom feeders and do best in a well-planted, mature aquarium. With a moderate activity level, they can be a great addition to a community tank, but their size and diet may be incompatible with smaller fish. Regular water changes and careful tank management are
Silver Dollar — Aquarium species
The Metynnis argenteus, known as the Silver Dollar fish, is a popular freshwater species with a distinctive silver color and disc-shaped body. They require a spacious tank and are best kept in groups to prevent bullying. Their peaceful nature makes them suitable for community tanks, but they are not known to school. They thrive in a well-maintained environme
Frequently Asked Questions
Can Fire Eel live with Silver Dollar?
With significant caution and a larger tank. Fire Eel and Silver Dollar 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 Fire Eel and Silver Dollar together?
A minimum of 100 gallons is recommended for keeping Fire Eel and Silver Dollar together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Fire Eel and Silver Dollar?
75–79°F
Is a Fire Eel aggressive toward a Silver Dollar?
Fire Eel is aggressive and Silver Dollar is semi. No major aggression issues are expected between these species.
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 | 57/100 |
| Ph | 100/100 |
| Temperament | 25/100 |
| Adult Size | 72/100 |
| Swim Zone | 92/100 |
| 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 | 180 gal | Best when keeping larger schools or reducing territorial pressure. |