Best Cleanup Crew For a Reef Tank | Algae | Substrate | Scavengers

Originally Posted STEVEN LANDAU JUNE 3RD, 2020

An aquarium is a closed system. As you feed your fish, waste builds up. Filtration and water changes help, but one of the best things you can do for a saltwater aquarium is to hire a cleanup crew (CUC for short). Whatever food your fish don’t digest becomes excess nutrients that fuel nuisance algae. That is why you see film algae on aquarium glass and green hair algae on the rock. The CUC is a group of invertebrates that eat waste and algae, getting into all the small places a gravel vacuum misses.  Adding a CUC makes your aquarium more like a natural aquatic environment, eases maintenance, and adds to viewing enjoyment. If you have a reef tank, a CUC can help keep algae from aggravating coral. Want to get a crew working for you? Read on and learn about your options.  

When choosing a CUC, think of the three different zones of your saltwater fish tank: glass, sand, and rock. Invertebrates clean in different zones In addition, some invertebrates are herbivores that eat algae, while others are omnivores and detritivores that eat waste. Pick a mix that covers all your needs. 

Cleanup Crew For a Reef Tank
Image Credits @Marine depot

Sand sifters

A lot of fish waste and uneaten food lands on the sand. Sand sifting invertebrates eat waste on and under the sand surface. Sand sifters also turn over the top layer of sand, which prevents dead spots where uneaten food can rot and anaerobic sand can build up. The sand is oxygenated as it is sifted, which improves the sand’s natural filtration ability.  

Algae eaters

Algae eaters, when used in combination, can tackle lots of different algae from the green hair algae and bubble algae that grow on rock to the film algae that also grows on the glass. Many snails take fine algae from the rocks and glass. Hermit crabs graze short hair and brush algae. Urchins eat virtually every algae including macroalgae and coralline algae, leaving rocks looking clean and new. Emerald crabs target bubble algae, aka valonia. 

Carnivores and Omnivores

Carnivores and omnivores eat a wide range of waste and algae. Hermit crabs, most of which also eat algae, are excellent aquarium janitors that comb the sand and rock for every morsel of food they can find. Nassarius snails are great at eating uneaten fish food, which if left will contribute to nitrate and phosphate in the tank. 

The cleanup crew reduces waste and nutrients, so they do not increase your bioload or reduce the number of fish your fish tank can handle. Pick a variety of species to clean different areas and substances in your tank.  Do keep in mind that many aquarium invertebrates are sensitive to nitrates. So, if you have high nitrate issues you may want to do a series of water changes to lower the nitrates before adding the CUC, which will then help keep your nitrates low.  


Many if not all Saltwater shrimps are reef safe. I have witnessed the odd one to occasionally nip at soft corals, this is very rare in this particular species. Many reef aquarium species that can be aggressive and very territorial when kept with other members of their species and even similar species. But shrimps and cleaner shrimps in particular are ok to be kept in the same reef aquarium as long as you provide a regular healthy and varied diet. This will calm and prevent any possibilities of fighting amongst the ranks.

Here’s some popular Reef cleaners

Name Good for?
Cerith Snailssand sifting omnivore
Fighting conch (Strombus spp.)sand sifting omnivore
Nassarius Snails sand sifting carnivore
Sand sifting starfishsandshifters
Turbo snailalgae Eaters
Pyramid snail (Tectus spp.) algae eaters
Turban snail (Trochus spp.) film algae eater
Hermit crabs red leg and blue leg hermit crabs are versatile omnivores
Urchins voracious algae eaters
Emerald crabvalonia bubble algae eating omnivore
Skunk Shrimpactive scavenger
Banded Cleaner Shrimpsand Scavenger
Camel Back Shrimpproficient cleaners

Our Favorites

1. Astraea snails

Astraea snails

Astraea snails are quickly recognized by their green conical shells with many levels of ridges, these snails make light work of green algae films from aquarium walls. However, they are more at home on and in between aquarium rocks. They are known from time to time to fall off and can sometimes land upside down. Unless you help them out by placing them the correct way up they can quickly become prey to other invertebrates and fish in the aquarium.

These snails have a huge appetite and so be careful how many you add to any one aquarium. One per 75-100 Gallons is often enough. Anymore and they could start to unbalance your stable reef environment.

2. Hermit Crabs

blue legged hermit crab

Hermit crabs are a valued member of the reef clean up crew and they’re fun to watch as they explore your tank. They will pick up detritus from the sand and rock work and graze at algae along the way.

May people like us love hermit crabs but those die-hard coral fans would be scared to death adding one of these crabs to their aquarium as they have been known to accidentally know over and damage corals and other invertebrates. I have also seen them attack other snails possibly as a food source and sometimes in search of a new shell.

3. Sandshifting Starfish

start fish

Many species of starfish are sand shifters and I’m sure from the name you’ll understand why we love them. Available in a wide range of colors and species you’ll be surprised how many wonderful starfish could become part of your cleanup crew.

One of our favourites it Astropecten polyacanthus, the sand sifting starfish or comb sea star, is a sea star of the family Astropectinidae. It is the most widespread species in the genus Astropecten, found throughout the Indo-Pacific region and commonly sold for the aquarium trade.

Final Thoughts

Every aquarium could do with a purposeful cleanup crew. Especially when they add so much color and interest to your reef aquarium. Many species of Freshwater fish that help clean up your aquarium are not the most colorful or interesting. Thankfully in a saltwater reef aquarium, the variety is much wider and more interesting. Not only in their colors and shapes but also in their day to day activities.