Can Goldfish (Comet / Common) and Hillstream Loach Live Together?

Goldfish (Comet / Common) is a peaceful species (1/10), while Hillstream Loach is peaceful (2/10). This modest difference means Hillstream Loach may occasionally assert dominance over Goldfish (Comet / Common).

Goldfish (Comet / Common) and Hillstream Loach both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

The safe temperature window for both species falls between 18°C and 24°C. Aim for the midpoint of this range (around 21.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range.

To house Goldfish (Comet / Common) and Hillstream Loach together, plan for an aquarium of at least 200 litres with a minimum length of 120 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.