The Tiger/Marble Hillstream Loach (Sewellia lineolata) is a highly specialized, ray-like freshwater fish native to central Vietnam. It is famous for its alien-like appearance and suction-cup fins. Additionally, it thrives in mature, highly oxygenated aquariums with strong currents and cool water (20 – 25°C). The loach also needs plenty of smooth, algae-covered rocks to graze on.

Key Care Requirements:

• Tank Size & Setup: A minimum of 60 liters is recommended for a small group. The tank should feature smooth gravel/sand, plenty of driftwood, and rounded stones. High water turnover and heavy aeration are critical for their health.
• Water Parameters: Maintain the pH between 6.5 and 7.5 and General Hardness (GH) around 10–20 dGH. Keep the water temperature on the cooler side 20°C to 24°C.
• Diet & Feeding: Often mislabeled as just an “algae eater,” these loaches primarily feed on diatom biofilm and microorganisms. Do not rely solely on existing algae; supplement their diet with high-quality sinking algae wafers, spirulina pellets, and occasional frozen foods like daphnia or brine shrimp.
• Tank Mates: Because they only reach about 6–7 cm (2-3 inches) in adulthood, they are entirely peaceful but should not be housed with large, predatory fish. They do well with other small community fish.