Compatibility Overview
Glowlight Danio and Swordtail 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 | Glowlight Danio | Swordtail | Verdict |
|---|---|---|---|
| Temperature | 72–82°F | 65–80°F | ✅ 72–80°F |
| pH Range | 6.0–7.5 | 7.0–8.3 | ⚠️ 7.0–7.5 (narrow) |
| Temperament | aggressive | peaceful | ❌ Risk |
| Adult Size | 1.6 in | 5 in | ⚠️ 3.1× difference |
| Min. Group | 6+ | 3+ | See below |
| Min. Tank Size | 75 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Glowlight Danio — Aquarium species
The Glowlight Danio is a popular freshwater fish known for its vibrant colors and active nature. They are ideal for beginners due to their hardiness and ease of care. These fish thrive in a well-maintained tank with plenty of swimming space and a school of their own kind.
→ Full Glowlight Danio care guide
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 Glowlight Danio live with Swordtail?
Generally not recommended. Glowlight Danio and Swordtail 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 Glowlight Danio and Swordtail together?
A minimum of 75 gallons is recommended for keeping Glowlight Danio and Swordtail together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Glowlight Danio and Swordtail?
72–80°F
Is a Glowlight Danio aggressive toward a Swordtail?
Glowlight Danio is aggressive and Swordtail is peaceful. 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 | 38/100 |
| Temperament | 30/100 |
| Adult Size | 38/100 |
| Swim Zone | 68/100 |
| Social Needs | 85/100 |
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. |