Harlequin Rasbora and Hillstream Loach Compatibility Overview
Harlequin Rasbora and Hillstream Loach can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.
| Factor | Harlequin Rasbora | Hillstream Loach | Verdict |
|---|---|---|---|
| Temperature | 72โ81ยฐF | 68โ75ยฐF | โ ๏ธ 72โ75ยฐF (narrow) |
| pH Range | 5.5โ7.5 | 6.0โ7.5 | โ 6.0โ7.5 |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 1.75 in | 2.6 in | โ Similar |
| Min. Group | 8+ | 4+ | See below |
| Min. Tank Size | 20 gallons (for both species) | โ | |
Compatibility Positives
Caution Points
Species Profiles
Harlequin Rasbora โ Trigonostigma heteromorpha
Active mid-level schooling fish with a distinctive black triangular patch. One of the best all-around community tank fish.
โ Full Harlequin Rasbora care guide
Hillstream Loach โ Sewellia lineolata
Sewellia lineolata, known as the Hillstream Loach, is a fascinating species for aquarists. These fish require a well-oxygenated, clear water environment with plenty of hiding spots. With a lifespan of 7 years, they are a long-term commitment. Their olive green color and slender body shape add a unique aesthetic to the tank.
Frequently Asked Questions
Can Harlequin Rasbora live with Hillstream Loach?
Yes, in a well-planned setup. Harlequin Rasbora and Hillstream Loach can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.
What tank size do I need for Harlequin Rasbora and Hillstream Loach together?
A minimum of 20 gallons is recommended for keeping Harlequin Rasbora and Hillstream Loach together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Harlequin Rasbora and Hillstream Loach?
72โ75ยฐF (narrow) โ inside Harlequin Rasbora's 72โ81ยฐF and Hillstream Loach's 68โ75ยฐF.
Is a Harlequin Rasbora aggressive toward a Hillstream Loach?
Harlequin Rasbora is peaceful and Hillstream Loach is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Harlequin Rasbora and Hillstream Loach
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 20 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 29 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 55 gal | Best when keeping larger schools or reducing territorial pressure. |