Compatibility Overview
Harlequin Rasbora and Kuhli Loach can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges, and neither poses a major aggression risk to the other. A minimum 55-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Harlequin Rasbora | Kuhli Loach | Verdict |
|---|---|---|---|
| Temperature | 72–81°F | 73–82°F | ✅ 73–81°F |
| pH Range | 5.5–7.5 | 5.5–7.0 | ✅ 5.5–7.0 |
| Temperament | peaceful | peaceful | ✅ Compatible |
| Adult Size | 1.75 in | 3.5 in | ⚠️ 2.0× difference |
| Min. Group | 8+ | 3+ | See below |
| Min. Tank Size | 55 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Harlequin Rasbora — Trigonostigma heteromorpha
Active mid-level schooling fish with a distinctive black triangular patch. One of the best all-around community tank fish.
→ Full Harlequin Rasbora care guide
Kuhli Loach — Pangio kuhlii
Eel-like bottom dwellers that are peaceful with all non-aggressive fish. Nocturnal and reclusive; need caves and soft substrate.
Frequently Asked Questions
Can Harlequin Rasbora live with Kuhli Loach?
Yes, in a well-planned setup. Harlequin Rasbora and Kuhli Loach can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges, and neither poses a major aggression risk to the other. A minimum 55-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Harlequin Rasbora and Kuhli Loach together?
A minimum of 55 gallons is recommended for keeping Harlequin Rasbora and Kuhli Loach together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Harlequin Rasbora and Kuhli Loach?
73–81°F
Is a Harlequin Rasbora aggressive toward a Kuhli Loach?
Harlequin Rasbora is peaceful and Kuhli Loach is peaceful. No major aggression issues are expected between these species.