Compatibility Overview
Pygmy Corydoras and Swordtail 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 75 gallons), dense planting, and close monitoring are essential.
| Factor | Pygmy Corydoras | Swordtail | Verdict |
|---|---|---|---|
| Temperature | 72–79°F | 65–80°F | ✅ 72–79°F |
| pH Range | 6.0–7.5 | 7.0–8.3 | ⚠️ 7.0–7.5 (narrow) |
| Temperament | peaceful | peaceful | ✅ Compatible |
| Adult Size | 1 in | 5 in | ❌ 5× difference |
| Min. Group | 6+ | 3+ | See below |
| Min. Tank Size | 75 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Pygmy Corydoras — Corydoras pygmaeus
Tiny armoured catfish that school in open water as well as on the substrate. Peaceful with all non-aggressive species.
→ Full Pygmy Corydoras 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 Pygmy Corydoras live with Swordtail?
With significant caution and a larger tank. Pygmy Corydoras and Swordtail 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 75 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Pygmy Corydoras and Swordtail together?
A minimum of 75 gallons is recommended for keeping Pygmy Corydoras and Swordtail together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Pygmy Corydoras and Swordtail?
72–79°F
Is a Pygmy Corydoras aggressive toward a Swordtail?
Pygmy Corydoras is peaceful and Swordtail is peaceful. Limited pH overlap (7.0–7.5) — maintain pH carefully within this narrow window.