Vanmanenia loach

Where they come from

Vanmanenia loaches are classic hillstream fish from fast, rocky streams in southern China and northern Vietnam. Picture clear, cool water blasting over cobbles, tons of dissolved oxygen, and stones coated in algae. That river energy is the whole key to keeping them happy at home.

Setting up their tank

Footprint matters more than height. A 30-inch long tank (75-90 cm) is a solid starting point for a small group. These guys want current and space to skim across rocks.

• Flow: Aim for 10-20x turnover. Powerheads pointed along the length of the tank work well. A river-manifold setup is even better.
• Oxygen: Strong surface agitation plus an airstone. Hillstreams suffer fast if O2 dips.
• Substrate: Sand or fine gravel with piles of smooth rounded stones and cobbles. Avoid sharp edges.
• Hardscape: Mix of flat rocks for grazing and a few caves/crevices for line-of-sight breaks.
• Plants: Optional. Hardy, low-profile types (Anubias, Microsorum) attached to rocks do fine in current.
• Lighting: Moderate to bright to grow algae on the rocks. I keep a spare tray of stones in a sunny tub to rotate in.
• Lid: Tight-fitting. They can climb glass and power cords.

• Temperature: 68-74 F (20-23 C). Short dips cooler are fine; avoid sustained heat.
• pH: 6.6-7.8
• Hardness: Soft to moderately hard is fine (roughly 2-12 dGH).
• Nitrates: Keep under 20 ppm. Lots of flow does not replace water changes.

What to feed them

They are biofilm grazers first. Give them rocks with green growth to rasp, then back it up with prepared foods. Think more greens, less meaty stuff.

• Daily: Algae and biofilm on stones. Rotate in pre-grown rocks from a tub if your tank is too clean.
• Staples: Repashy Soilent Green/Super Green, high-quality algae wafers, spirulina pellets.
• Veggies: Blanched zucchini, spinach, kale chips (quick blanch), sliced cucumber.
• Treats (2-3x/week): Frozen daphnia, baby brine shrimp, or small amounts of bloodworms. Go light on protein to avoid bloat.

How they behave and who they get along with

They scoot, cling, and spar. Expect short chases and side-by-side shoving matches on favorite rocks. It looks intense but rarely causes damage if the group and space are right.

• Group size: 4-6+ spreads out the squabbles.
• Good neighbors: Other hillstream loaches, small danios, white clouds, Tanichthys-like minnows, peaceful gobies (Stiphodon/Rhinogobius with similar temps), and shrimp in well-planted setups.
• Avoid: Big or pushy fish, warmwater species, long-finned slow fish, and heavy feeders that hog all the food.

Breeding tips

Spawning in home tanks is rare and not something I would count on. If you want to try, set up a dedicated stream tank and think seasonally.

• Sexing: Females are usually rounder; males may have more pronounced head/pectoral features.
• Layout: Deep bed of mixed pebbles and river stones with strong linear flow and high oxygen.
• Season cues: Cool period with heavy feeding, then gradual temp rise and big water changes using slightly cooler water.
• Eggs: Likely scattered into gaps under stones. Adults may eat them, so use pebble trays you can lift to a rearing tank.
• Fry: Very small and algae-focused at first. Biofilm rocks, powdered spirulina, and green water help.

Common problems to watch for

• Overheating and oxygen crashes: The big killer. Anything above 75 F without extra aeration is risky.
• Starvation in clean tanks: Bare, algae-free stones lead to weight loss. Grow biofilm or feed gel foods often.
• Import skinny and parasites: Quarantine new fish. Many arrive thin and may carry flukes. Use gentler meds and boost oxygen during treatment.
• Bloat from rich foods: Too much bloodworm or high-protein pellets can swell them up. Keep protein as a treat.
• Abrasions: Rough rock or frantic chasing on sharp decor causes scrapes. Use smooth stones and keep water pristine to prevent infections.
• Medication sensitivity: Go half-dose with copper/formalin/malachite green. Prioritize heat-free methods and heavy aeration.