Can Cardinal Tetra live with Molly?
Caution — with care
Why
- Only a narrow pH overlap — keep both around 7.
- Molly is large enough to threaten a small Cardinal Tetra — usually fine once both are adult, but watch new additions.
- No overlapping water hardness: Cardinal Tetra wants 1–6 dGH but Molly wants 12–30 dGH.
Sweet spot: both do well at 73–81°F and pH 7–7 — aim there.
Side-by-side
| Cardinal Tetra | Molly | |
|---|---|---|
| Temperature | 73–81°F | 72–82°F |
| pH | 5–7 | 7–8.5 |
| Hardness (GH) | 1–6 dGH | 12–30 dGH |
| Adult size | 2" | 4" |
| Temperament | Peaceful | Peaceful |
| Min tank | 15 gal | 30 gal |
Together, plan on at least 30 gallons.
How to make it work
- Target the overlapping water-parameter range and acclimate slowly.
Sort it with: GH remineraliser → Aquarium Co-Op
Where to buy
- Cardinal Tetra: buy at Flip Aquatics · Flip Aquatics live-arrival guarantee
- Molly: buy at Flip Aquatics · Flip Aquatics live-arrival guarantee
Live-animal shipping: add a heat pack below 50°F, expect weather holds above 90°F, and schedule delivery for a moderate week when someone can receive it promptly.
Build a full tank around this stocking →Everything compatible with Cardinal Tetra · …with Molly