Marine Snail Species Guide: Beyond the Basics

Snails: The Unsung Heroes of Every Reef Tank

A properly selected snail team does more for a tank's long-term health than almost any other purchase. Different species target different problems — film algae, hair algae, detritus, sand maintenance — and knowing which snail does what saves a lot of wasted effort.

The Algae Grazers

Turbo Snails — Big, powerful grazers that bulldoze through film algae and diatoms. Very effective in new tanks. Downsides: clumsy, can't right themselves, and some species from cooler waters have shorter lifespans in warmer reef tanks.

Trochus Snails — Generally considered the upgrade from turbos. Similar grazing ability, but they can right themselves, tolerate warmer temperatures, breed in reef tanks, and live longer.

Astrea Snails — Good algae grazers, small and efficient. Can't right themselves like turbos. Cheap and effective as part of a mixed CUC.

Nerite Snails — Tiny, tenacious grazers that get into spots larger snails can't reach. They do lay small white eggs on rocks and glass that never hatch in saltwater.

The Sandbed Crew

Nassarius Snails — Essential for sandbeds. They burrow under the surface and erupt when they smell food, eating detritus and decaying organic matter. They also keep the sandbed aerated.

Cerith Snails — Versatile snails that graze algae on rocks AND burrow through sand. All-rounders and a solid CUC backbone. They breed in captivity too.

The Specialists

Stomatella Snails — Usually hitchhike in on live rock. Small, flat, incredible algae grazers and completely reef-safe. They breed readily — a welcome free addition to any CUC.

Fighting Conch — Brilliant sand-sifters. Need a decent sandbed area. One per 150 litres or so — they can deplete sandbed fauna if overstocked.

How Many Snails?

• New tank: 1 snail per 4–5 litres to tackle the initial algae bloom, then let numbers naturally adjust
• Mature tank: fewer — a well-balanced reef doesn't produce much excess algae

Mix species for complete coverage rather than going all one type.

Browse marine snails and CUC from UK sellers — mixed CUC packs are great value for new setups.