Harlequin Rasbora and Royal Gramma Compatibility Overview
Harlequin Rasbora and Royal Gramma are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. Their pH ranges do not meet: Harlequin Rasbora wants 5.5โ7.5 and Royal Gramma wants 8.1โ8.4. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Harlequin Rasbora | Royal Gramma | Verdict |
|---|---|---|---|
| Temperature | 72โ81ยฐF | 72โ82ยฐF | โ 72โ81ยฐF |
| pH Range | 5.5โ7.5 | 8.1โ8.4 | โ No overlap |
| Temperament | peaceful | semi | โ ๏ธ Monitor |
| Adult Size | 1.75 in | 3.0 in | โ Similar |
| Min. Group | 8+ | 1+ | See below |
| Min. Tank Size | 20 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
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
Royal Gramma โ Gramma loreto
The Royal Gramma, known for its vibrant blue coloration, is a popular saltwater fish among beginners and experienced aquarists alike. It requires a well-maintained tank with plenty of swimming space and a moderate current. With a peaceful temperament and a relatively easy care routine, the Royal Gramma can be a great addition to a community tank.
Frequently Asked Questions
Can Harlequin Rasbora live with Royal Gramma?
Generally not recommended. Harlequin Rasbora and Royal Gramma are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. Their pH ranges do not meet: Harlequin Rasbora wants 5.5โ7.5 and Royal Gramma wants 8.1โ8.4. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Harlequin Rasbora and Royal Gramma together?
A minimum of 20 gallons is recommended for keeping Harlequin Rasbora and Royal Gramma together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Harlequin Rasbora and Royal Gramma?
72โ81ยฐF โ inside Harlequin Rasbora's 72โ81ยฐF and Royal Gramma's 72โ82ยฐF.
Is a Harlequin Rasbora aggressive toward a Royal Gramma?
Harlequin Rasbora is peaceful and Royal Gramma is semi. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Harlequin Rasbora and Royal Gramma
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 30 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 55 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 75 gal | Best when keeping larger schools or reducing territorial pressure. |