Reef Tank Clean-Up Crew: What to Add and How Many
By Melbourne Tropical Team Β· 2 min read
A good clean-up crew keeps algae and waste under control. Here's what each reef invert does, which to choose, and how many you really need.
What a clean-up crew does
A 'clean-up crew' (CUC) is a team of reef-safe invertebrates that graze algae, sift sand and scavenge leftover food. They don't replace water changes or good husbandry, but they keep nuisance algae and detritus in check and make your reef look clean.
The main members
Build a balanced team rather than lots of one thing:
- Snails (Turbo, Trochus, Astrea) - the best algae grazers for glass and rock.
- Nassarius & Cerith snails - sift and clean the sand bed.
- Hermit crabs (blue leg, scarlet) - scavenge algae and food (give them spare shells).
- Cleaner & peppermint shrimp - pick parasites and eat Aiptasia pests.
- Emerald crab - one of the few things that eats bubble algae.
- Brittle/serpent stars - mop up leftover food in the rockwork.
How many should you add?
Less is more - a clean-up crew that is too big will run out of food and starve. A rough starting guide is around 1 snail per 4-8 litres plus a few hermits and a shrimp or two, then adjust based on how much algae you actually have. Add them gradually once your tank has matured enough to grow some algae for them to eat. See our reef invert guides for each species' role and care.
Avoid these mistakes
Don't add the whole crew to a brand-new tank (nothing to eat yet), don't rely on hermit crabs alone, and remember invertebrates are extremely sensitive to copper - never use copper medications in the display. Always drip-acclimate new inverts slowly.