Compatibility Overview
Diamond Tetra and Hillstream Loach can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 40 gallons), dense planting, and close monitoring are essential.
| Factor | Diamond Tetra | Hillstream Loach | Verdict |
|---|---|---|---|
| Temperature | 72–82°F | 64–73°F | ⚠️ 72–73°F (narrow) |
| pH Range | 6.0–7.5 | 6.5–7.5 | ✅ 6.5–7.5 |
| Temperament | semi | semi | ⚠️ Monitor |
| Adult Size | 1.2 in | 2.0 in | ✅ Similar |
| Min. Group | 6+ | 1+ | See below |
| Min. Tank Size | 40 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Diamond Tetra — Aquarium species
The Diamond Tetra is a popular freshwater fish known for its vibrant colors and peaceful nature. It is well-suited for community tanks and can thrive in a variety of water conditions. With a moderate activity level and a preference for schools, this species is a great addition to any beginner or intermediate aquarist's tank.
→ Full Diamond Tetra care guide
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
Frequently Asked Questions
Can Diamond Tetra live with Hillstream Loach?
With significant caution and a larger tank. Diamond Tetra and Hillstream Loach can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 40 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Diamond Tetra and Hillstream Loach together?
A minimum of 40 gallons is recommended for keeping Diamond Tetra and Hillstream Loach together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Diamond Tetra and Hillstream Loach?
72–73°F (narrow)
Is a Diamond Tetra aggressive toward a Hillstream Loach?
Diamond Tetra is semi and Hillstream Loach is semi. Their preferred temperature ranges have little or no safe overlap.
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 | 11/100 |
| Ph | 100/100 |
| 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 | 40 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 | 90 gal | Best when keeping larger schools or reducing territorial pressure. |