Can Black Neon Tetra live with Swordtail?
Light caution
Why
- Only a narrow water hardness overlap — keep both around 12–12 dGH.
- Swordtail is semi-aggressive — give the peaceful Black Neon Tetra plenty of space, cover and broken sight lines.
- Large size gap (Swordtail 5.5" vs Black Neon Tetra 1.5") — watch that the smaller one gets its share at feeding time.
Sweet spot: both do well at 72–82°F and pH 7–7.5 — aim there.
Side-by-side
| Black Neon Tetra | Swordtail | |
|---|---|---|
| Temperature | 72–82°F | 72–82°F |
| pH | 5.5–7.5 | 7–8.4 |
| Hardness (GH) | 2–12 dGH | 12–30 dGH |
| Adult size | 1.5" | 5.5" |
| Temperament | Peaceful | Semi-aggressive |
| Min tank | 15 gal | 29 gal |
Together, plan on at least 29 gallons.
How to make it work
- Target the overlapping water-parameter range and acclimate slowly.
- Use a larger, well-decorated tank with sightline breaks, keep everyone well-fed, and add the calmer fish first.
Sort it with: GH remineraliser
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Design a tank with Black Neon Tetra, Swordtail →Everything compatible with Black Neon Tetra · …with Swordtail