Can Carnival / Polka Dot Freshwater Crab live with Harlequin Rasbora?
Caution — with care
Why
- Carnival / Polka Dot Freshwater Crab can grab Harlequin Rasbora while it sleeps — only fast mid/top-water fish are reasonably safe.
- Only a narrow pH overlap — keep both around 7.5–7.5.
Sweet spot: both do well at 75–80°F and pH 7.5–7.5 — aim there.
Side-by-side
| Carnival / Polka Dot Freshwater Crab | Harlequin Rasbora | |
|---|---|---|
| Temperature | 75–82°F | 72–80°F |
| pH | 7.5–8 | 6–7.5 |
| Hardness (GH) | 8–15 dGH | 2–12 dGH |
| Adult size | 1.5" | 1.75" |
| Temperament | Peaceful | Peaceful |
| Min tank | 10 gal | 15 gal |
Together, plan on at least 15 gallons.
How to make it work
- Only combine with fast, mid/top-water fish and give the tankmates plenty of escape routes.
- Target the overlapping water-parameter range and acclimate slowly.
Where to buy
- Harlequin Rasbora: buy at The Shrimp Farm · The Shrimp Farm 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.
Design the whole tank, not just the stocking
Skapelab plans a complete, buildable planted aquarium around your fish — a hand-illustrated layout, the exact plants and hardscape, a placement map, and a full equipment and shopping list. Free.
Design a tank with Carnival / Polka Dot Freshwater Crab, Harlequin Rasbora →Everything compatible with Carnival / Polka Dot Freshwater Crab · …with Harlequin Rasbora