Compatibility Overview
Harlequin Rasbora and Yellow Tang are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
| Factor | Harlequin Rasbora | Yellow Tang | Verdict |
|---|---|---|---|
| Temperature | 72–81°F | 73–81°F | ✅ 73–81°F |
| pH Range | 5.5–7.5 | 8.0–8.5 | ❌ No overlap |
| Temperament | peaceful | semi | ⚠️ Monitor |
| Adult Size | 1.75 in | 2.4 in | ✅ Similar |
| Min. Group | 8+ | 1+ | See below |
| Min. Tank Size | 55 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
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
Yellow Tang — Aquarium species
The Yellow Tang is a popular and vibrant fish suitable for beginners. With its bright yellow color and blue stripes, it adds a striking contrast to the aquarium. They are generally peaceful and can be kept in a community tank, though they may be nippy with certain tankmates. They require a well-maintained tank with plenty of swimming space and a varied diet.
Frequently Asked Questions
Can Harlequin Rasbora live with Yellow Tang?
Generally not recommended. Harlequin Rasbora and Yellow Tang are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
What tank size do I need for Harlequin Rasbora and Yellow Tang together?
A minimum of 55 gallons is recommended for keeping Harlequin Rasbora and Yellow Tang together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Harlequin Rasbora and Yellow Tang?
73–81°F
Is a Harlequin Rasbora aggressive toward a Yellow Tang?
Harlequin Rasbora is peaceful and Yellow Tang is semi. These animals require different water types and cannot share one aquarium.
Related Compatibility Guides
Compatibility score breakdown
The overall score is weighted across water chemistry, behavior, adult size, swimming zone, and social needs. A score is a planning aid—not a guarantee for individual fish.
| Factor | Score |
|---|---|
| Temperature | 100/100 |
| Ph | 0/100 |
| Temperament | 75/100 |
| Adult Size | 100/100 |
| Swim Zone | 68/100 |
| Social Needs | 92/100 |
Tank size scenarios
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 55 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 75 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 125 gal | Best when keeping larger schools or reducing territorial pressure. |