Banded Trochus Snail — Trochus histrio

Efficient film-algae grazer. Reef-safe.

Quick facts

• Size: 3–5 cm shell

• Temperament: Peaceful

• Reef-safe: Yes

• Role: Film algae, diatoms, light cyano grazer

• Self-righting: Usually can flip itself over

Aquarium requirements

• Tank: ≥ 30 l; mature rock and glass surfaces.

• Water: pH 8.1–8.4, salinity 1.025–1.026, temp 24–26 °C; NH3/NO2 0, NO3 <20 ppm.

• Flow: Low–moderate; avoid unguarded strong intakes.

Diet

• Primary: Film algae, diatoms, biofilm.

• Supplement: Algae wafers or small pellet crumbs if the tank is very clean.

Behavior and compatibility

• Active day and night; grazes on rock, glass, and equipment.

• Safe with corals and most fish.

• Avoid predators that eat snails (certain wrasses, triggers, puffers).

Acclimation and care

• Drip acclimate 30–45 min; match salinity closely.

• Do not expose to air if possible; place upright near hard surfaces.

• If upside down for long, assist flipping.

Stocking guide

• 30–60 l: 2-10 snails

• 120 l: 5-10 snails

• 250 l+: 10-20+ snails

Notes

• Good alternative to Astraea; better at self-righting.

• Not a cure for hair algae alone. Combine with other herbivores for full control.