Trochus Snail

Trochus spp.

A workhorse algae-grazing snail that can flip itself back over — the reliable cleanup pick.

Difficulty: BeginnerCleanup crewReef-safe

The trochus snail (Trochus spp.) is a workhorse of the reef cleanup crew — a cone-shelled grazer that mows film algae, diatoms and cyanobacteria off glass, rock and sand. Its standout trick is that it can flip itself back over when it topples, so unlike many reef snails it doesn't quietly starve on its back. It's fully reef-safe, hardy, and the only real needs are a cycled tank, slow acclimation, and enough algae to graze.

📊 What keepers actually ask: The recurring questions are “what's the best cleanup snail?” (trochus is a top pick precisely because it self-rights) and “how many do I need?” — start around one per 5 gallons and adjust to your algae.

Care at a glance

Adult size	≈1–1.5 in.
Minimum tank	Any established reef tank; stock roughly one snail per 5 gallons so each has enough algae.
Temperature	75–82°F (24–28°C).
pH	8.1–8.4.
Specific gravity	1.023–1.026 (reef-standard ≈35 ppt).
Other targets	Standard reef calcium and alkalinity keep the shell healthy; like all inverts it has zero tolerance for copper.
Diet	Herbivore — grazes film algae, diatoms and cyanobacteria off glass, rock and substrate with its radula. Offer nori if the tank gets too clean.
Temperament	Peaceful and fully reef-safe; happy singly or in groups.
Reef-safe	Yes — it grazes algae and won't touch corals.
Natural range	Indo-Pacific.

Beginner-friendly, done right. One of the easiest and most reliable cleanup snails — the two things that catch people out are both about inverts, not trochus specifically. They're sensitive to nitrate and to salinity swings, so only add them to a properly cycled tank and drip-acclimate slowly (a snail dropped into a new tank often ends up an empty shell). And don't overstock — roughly one per 5 gallons — or they'll graze the tank bare and then starve. No copper, ever.

The fish store gets these wrong

Common myths, kindly corrected — no shame for having believed them.

“All reef snails are the same cleanup crew.” They divide the labour: a trochus grazes algae off surfaces, while a nassarius sifts the sand for leftover food. You generally want both.
“More snails = a cleaner tank.” Overstock and they strip the algae, then starve. Match the number to the algae you actually have (≈one per 5 gallons to start).
“Snails are indestructible.” They're inverts — sensitive to nitrate, salinity swings and copper. A new or medicated tank is what usually kills them.

Before you buy

A cycled, established tank with algae to graze — not a brand-new setup.
Drip-acclimate slowly; never any copper in the tank.
Stock to your algae (≈one per 5 gallons) so they don't starve.
Pair with a sand-sifting snail (like nassarius) for full cleanup coverage.

Signs something's wrong

A struggling invert is usually telling you about water quality, acclimation, or (for shrimp and crabs) a fresh moult — here's what to watch for:

Empty shell / a hermit crab wearing it — the snail has died, usually from an un-cycled tank, a salinity swing or copper.
Sitting still for days and not grazing — check parameters, and whether there's any algae left to eat.
Repeatedly falling and (rarely) not righting — often nothing to grip; make sure it can reach rock/glass.

Never

Never add snails to an un-cycled or newly-set-up tank — they need a mature, algae-grown system.
Never dose copper medications with inverts in the tank.
Never drop them straight in — drip-acclimate (salinity shock kills snails fast).
Never overstock — starving a big cleanup crew is a slow, common mistake.

Common trochus snail questions

What do trochus snails eat?

They're herbivores that graze film algae, diatoms and cyanobacteria off glass, rock and the substrate. If your tank runs very clean, offer a little nori so they don't starve.

Can trochus snails flip themselves back over?

Yes — that's their signature advantage. Unlike many reef snails (such as Astrea), a trochus can usually right itself when it topples, so it's far less likely to end up stranded on its back and starve.

How many trochus snails do I need?

A common starting point is about one per 5 gallons, then adjust to how much algae you actually have. Overstocking leads to a clean tank and then starving snails.

Are trochus snails reef-safe?

Completely — they graze algae and won't bother corals or other invertebrates. They're peaceful and can be kept singly or in groups.

Why did my trochus snail die?

Most snail losses come from being added to an un-cycled tank, a salinity swing, or copper in the water. Always add snails to a mature, cycled system, drip-acclimate slowly, and never use copper medications with inverts.

Sources & further reading

This guide was written and fact-checked against these authorities. It's honest, general guidance — not a diagnosis, and not a substitute for an aquatic vet or your own test kit:

Bulk Reef Supply — How To Care For Trochus Snails — care, reef-safe, cleanup role
AlgaeBarn — Utilizing the Trochus Snail — algae grazing, self-righting, stocking rate
Saltwater Aquarium Blog — Trochus Snail Care — size, diet, reef facts

Written and fact-checked by The Coralkin Team against marine-aquarist sources — if your trochus snail is struggling, it's almost always water quality, acclimation or a moult — check those first and ask an experienced reefer. We never guess a care number.

🔬 Review status: team-written and fact-checked against cited sources · not yet reviewed by a marine vet. How we research & fact-check →

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