Saltwater clean-up crew

A clean-up crew handles algae, leftover food and detritus before they become problems. Most of the inverts here do that work, while a few, like the harlequin shrimp and the porcelain crabs, clean nothing. Most profiles cover what each one eats and any reef-safety caveats.

At a glance

Tank size
5–40 gal
5 gal (20 L) to 40 gal (150 L); half the list needs 11 gal (40 L) or more
Temperature
73–81°F
23–27°C, most of the list
pH
8.1–8.4
Most of the list
Difficulty
43 easy
4 medium · 1 difficult
Temperament
33 peaceful
13 mostly peaceful · 2 aggressive
Reef safety
32 reef safe
14 reef safe with caution · 2 not reef safe

48 species

Start here

The first crew for a new reef

The trochus snail is the grazer to start with, marked beginner at 1.2 inches (3 cm). It cleans glass and rock and rights itself when it falls. It may spawn in the tank, but its larvae rarely settle. The cerith snail works the sand and the glass at 1.6 inches (4 cm), and the nassarius snail lives in the sand and eats the food the fish missed. The blue-leg hermit crab is 1 inch (2.5 cm), marked beginner and reef safe, and picks over the rock all day. The scarlet reef hermit crab is the calmer hermit, marked peaceful at 1.6 inches (4 cm). The skunk cleaner shrimp is marked beginner at 2.4 inches (6 cm) for 20 gallons (75 liters) and cleans the fish rather than the tank.

The rule

How a clean-up crew works

Each crew animal cleans one surface. The trochus and turbo snails graze rock and glass, and the ceriths and nassarius work the sand. The hermits pick at whatever the snails leave, and the peppermint shrimp eats Aiptasia. The peacock mantis shrimp and the anemone hermit crab eat snails and hermits, and both are marked not reef safe. The harlequin shrimp, the two porcelain crabs and the coral guard crab do not clean anything. A crew is a small mix of each rather than a crowd of one, and it goes in after the cycle, once there is algae to eat, because a crew added to a bare tank starves. Hermits need spare shells or they take one from a snail. And every invertebrate here is drip acclimated, because a salinity swing that a fish shrugs off kills a snail.

  1. 01

    A mix, not a crowd

    Each crew species cleans one surface

  2. 02

    After the cycle

    A crew in a bare tank starves

  3. 03

    Spare shells

    Or the hermits take them from the snails

  4. 04

    Drip acclimate

    Salinity swings kill invertebrates

Snails

Snails for the glass, the rock and the sand

The astraea snail grazes like a trochus at 1 inch (2.5 cm) but cannot right itself, so it needs turning over when it falls. The Mexican turbo snail is the heavy grazer at 2.4 inches (6 cm), marked easy, and it plows through hair algae and loose frags alike. The marine nerite snail cleans glass at 1 inch (2.5 cm). The bumble bee snail is a 0.8 inch (2 cm) scavenger that hunts worms and leftovers in the rock. The stomatella is the hitchhiker that arrives on live rock and grazes at night. The fighting conch plows the sand bed at 3.1 inches (8 cm) for 20 gallons (75 liters), marked easy.

Crabs

Crabs, hermits and the ones to watch

The emerald crab eats bubble algae that few other animals touch, 2.4 inches (6 cm) for 11 gallons (40 liters). The red mithrax crab eats some too. The emerald crab carries a caution because a hungry one goes after small fish, snails, hermits and shrimp. The Halloween hermit crab is 2 inches (5 cm) of orange and red with the same caution, big enough to bulldoze. The electric blue hermit crab is marked reef safe and peaceful at 2 inches (5 cm). The Mexican red-leg hermit crab is the small one at 1 inch (2.5 cm), marked beginner. The porcelain anemone crab filters plankton from the water and lives in an anemone, marked peaceful at 3 inches (7.5 cm). The Sally Lightfoot crab is a fast grazer at 3.1 inches (8 cm) that grows into an opportunist.

Shrimp

Cleaners, a digger and the harlequin

The peppermint shrimp is marked beginner at 2 inches (5 cm) for 11 gallons (40 liters), and it is the one crew member that eats Aiptasia anemones. The fire shrimp is a cleaner that hides more than the skunk, marked easy for 20 gallons (75 liters). The sexy shrimp stays at 1.2 inches (3 cm) in 5 gallons (20 liters) and lives among anemones and corals. The tiger pistol shrimp pairs with a watchman goby and digs a burrow. The coral banded shrimp is 2.4 inches (6 cm) for 30 gallons (115 liters) and carries a caution because it grabs small fish and other shrimp. The harlequin shrimp eats only starfish, so it cleans nothing and needs feeding.

By the numbers

FAQ

Common questions

How many snails and hermits does a reef need?

A few of each kind to start, added a couple of weeks after the cycle, and more only when the algae outpaces them. A crowd starves once the tank is clean.

Do hermit crabs kill snails?

They take shells, and a hermit that has outgrown its shell will kill a snail for it. Keep a handful of empty shells in the tank in a range of sizes.

Which crabs are reef safe?

The blue-leg, scarlet reef, scarlet zebra, Mexican red-leg and electric blue hermits are marked reef safe. The two porcelain crabs, the pom-pom crab and the coral guard crab are marked reef safe too. The emerald, strawberry, decorator, red mithrax, Sally Lightfoot and arrow crabs carry a caution. The Halloween and staghorn hermits carry one too. The anemone hermit crab is the one crab marked not reef safe.

What eats hair algae and bubble algae?

The astraea turbo snail and the Mexican turbo snail graze hair algae. The blue-leg, scarlet reef, electric blue, Halloween and Mexican red-leg hermits graze it too. The emerald crab and the red mithrax crab eat bubble algae. Nothing on this page fixes the nutrients that grow either.

Can a FOWLR tank have a clean-up crew?

Not for long. Triggers, puffers and the big wrasses eat snails, hermits and shrimp, which is why the FOWLR list exists.

When do I add the clean-up crew?

After the cycle finishes and the first algae appears on the glass. Drip acclimate every animal over an hour, because invertebrates do not tolerate a salinity jump.

Index

All saltwater clean-up crew

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