Goldfish and Swordtail Compatibility Overview
Short answer: Yes. Both do well at 65-74°F and both are peaceful. Match the tank size and group size in the table below and both should do well.
Goldfish and Swordtail can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 100-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Goldfish | Swordtail | Verdict |
|---|---|---|---|
| Temperature | 50–74°F | 65–80°F | ✅ 65–74°F |
| pH Range | 6.5–8.0 | 7.0–8.3 | ✅ 7.0–8.0 |
| Temperament | peaceful | peaceful | ✅ Compatible |
| Adult Size | 12 in | 5 in | ⚠️ 2.4× difference |
| Min. Group | 1+ | 3+ | See below |
| Min. Tank Size | 100 gallons (for both species) | — | |
Compatibility Positives
Caution Points
Species Profiles
Goldfish — Carassius auratus
Classic pond and aquarium fish that prefer cool water. Heavy waste producers that require robust filtration. Will eat small fish and shrimp.
Swordtail — Xiphophorus hellerii
Hardy livebearer with a distinctive elongated lower tail fin in males. Peaceful community fish that tolerate a wide temperature range.
Frequently Asked Questions
Can Goldfish live with Swordtail?
Yes, in a well-planned setup. Goldfish and Swordtail can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 100-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Goldfish and Swordtail together?
A minimum of 100 gallons is recommended for keeping Goldfish and Swordtail together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Goldfish and Swordtail?
65–74°F — inside Goldfish's 50–74°F and Swordtail's 65–80°F.
Is a Goldfish aggressive toward a Swordtail?
Goldfish is peaceful and Swordtail is peaceful. No major aggression issues are expected between these species.
More Good Tank Mates for Goldfish and Swordtail
The highest-scoring compatible partners for each species in our compatibility data.
For Goldfish
- Weather Loach — 98/100
- Bristlenose Pleco — 87/100
- Denison Barb — 87/100
- Koi — 86/100
- Yoyo Loach — 77/100
For Swordtail
- Bristlenose Pleco — 91/100
- Mystery Snail — 91/100
- Platy — 90/100
- Corydoras — 89/100
- Molly — 89/100
Related Compatibility Guides
Tank Size for Goldfish and Swordtail
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. |