Tank Setup — The River Tank
Hillstream loaches require a specific setup that mimics fast-flowing mountain streams:
- Tank size: 20 gallons minimum
- Flow: Strong — the most critical requirement. Use a powerhead or wave maker to create strong, directional flow. They need high oxygenation and water movement.
- Temperature: Cool — 65–75°F. They do not tolerate warm water well.
- Substrate: Smooth river rocks and pebbles — they cling to and graze on these surfaces
- Surfaces: Provide lots of smooth, flat rocks for grazing. They eat the biofilm that grows on rock surfaces in high-flow environments.
Water Parameters
- Temperature: 65–75°F (18–24°C) — warmer water holds less oxygen, which they need
- pH: 6.5–7.5
- GH: 4–12 dGH
- Oxygen: High — strong flow and surface agitation are essential
Diet & Feeding
Primarily biofilm and algae grazers. In a mature tank with strong flow and smooth rocks, biofilm grows continuously on surfaces. Supplement with:
- Algae wafers (Hikari Algae Wafers, Repashy Soilent Green)
- Blanched zucchini and cucumber
- Spirulina wafers
Ensure your tank is mature (3+ months running) before adding hillstream loaches — they need established biofilm.
Frequently Asked Questions
Are hillstream loaches good algae eaters?
Excellent — on par with otocinclus for soft algae and biofilm. They are especially effective on smooth surfaces. They will not eat tough algae like BBA or green spot algae.
Can hillstream loaches live in a normal tropical tank?
Not ideally. They need cooler water (under 75°F) and strong flow. Standard tropical community tanks are too warm and too still for them.