Compatibility Overview
Hillstream Loach 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 | Hillstream Loach | Yellow Tang | Verdict |
|---|---|---|---|
| Temperature | 64–73°F | 73–81°F | ⚠️ 73–73°F (narrow) |
| pH Range | 6.5–7.5 | 8.0–8.5 | ❌ No overlap |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 2.0 in | 2.4 in | ✅ Similar |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 20 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Hillstream Loach — Aquarium species
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. Despite their moderate activity le
→ Full Hillstream Loach 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 Hillstream Loach live with Yellow Tang?
Generally not recommended. Hillstream Loach 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 Hillstream Loach and Yellow Tang together?
A minimum of 20 gallons is recommended for keeping Hillstream Loach and Yellow Tang together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Hillstream Loach and Yellow Tang?
73–73°F (narrow)
Is a Hillstream Loach aggressive toward a Yellow Tang?
Hillstream Loach is semi 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 | 0/100 |
| Ph | 0/100 |
| Temperament | 62/100 |
| Adult Size | 100/100 |
| Swim Zone | 92/100 |
| 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 | 26 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 40 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. |