Cardinal Tetra and Hillstream Loach Compatibility Overview
Cardinal Tetra and Hillstream Loach can potentially coexist, but the combination requires careful attention. Their ranges meet only at 73โ75ยฐF, which leaves no margin for a heater drifting or a warm room. Their pH ranges overlap only partly, so aim for the shared band and keep it steady. A larger tank (minimum 20 gallons), dense planting, and close monitoring are essential.
| Factor | Cardinal Tetra | Hillstream Loach | Verdict |
|---|---|---|---|
| Temperature | 73โ82ยฐF | 68โ75ยฐF | โ ๏ธ 73โ75ยฐF (narrow) |
| pH Range | 4.5โ7.0 | 6.0โ7.5 | โ 6.0โ7.0 |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 1.5 in | 2.6 in | โ Similar |
| Min. Group | 6+ | 4+ | See below |
| Min. Tank Size | 20 gallons (for both species) | โ | |
Compatibility Positives
Caution Points
Species Profiles
Cardinal Tetra โ Paracheirodon axelrodi
Brilliant red-and-blue schooling fish from the Rio Negro. Prefers soft, acidic, warm water โ a natural companion for discus.
โ Full Cardinal Tetra 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 Cardinal Tetra live with Hillstream Loach?
With significant caution and a larger tank. Cardinal Tetra and Hillstream Loach can potentially coexist, but the combination requires careful attention. Their ranges meet only at 73โ75ยฐF, which leaves no margin for a heater drifting or a warm room. Their pH ranges overlap only partly, so aim for the shared band and keep it steady. A larger tank (minimum 20 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Cardinal Tetra and Hillstream Loach together?
A minimum of 20 gallons is recommended for keeping Cardinal Tetra and Hillstream Loach together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Cardinal Tetra and Hillstream Loach?
73โ75ยฐF (narrow) โ inside Cardinal Tetra's 73โ82ยฐF and Hillstream Loach's 68โ75ยฐF.
Is a Cardinal Tetra aggressive toward a Hillstream Loach?
Cardinal Tetra is peaceful and Hillstream Loach is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Cardinal Tetra 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. |