Including a mix of janitorial invertebrates in your saltwater aquarium will help you keep your saltwater aquarium clean, the sand bed sparkling, and algae under control.

When it comes to selecting a clean-up crew for your saltwater aquarium, the vast array of choices can be a little daunting to the beginning aquarist. This article aims to make the choices a little easier.

The clean-up crew is a combination of invertebrates (and sometimes other animals, but this article only addresses invertebrates) that each addresses one of the following maintenance issues in the aquarium:

  • Algae Control
  • Sand Sifting
  • Detritus Control

Algae Control

Snails, crabs and sea slugs can all be used effectively for algae control in the saltwater aquarium. Consider the following snails:

  • Astraea Snails
  • Nerite Snails
  • Trochus Snails
  • Turbo Snails

Most of the snails aquarists keep in their aquaria to control algae are from four families of gastropods:

  • Trochidae (Trochus Snails, Margarita Snails)
  • Turbinidae (Turbo Snails, Astraea Snails)
  • Neritidae (Nerite Snails)
  • Cerithiidae (Cerith Snails)

It’s pretty easy to tell Nerite and Cerith Snails apart, but there is a lot of confusion when it comes to the two most common families of snails: Trochidae and Turbinidae. These snails are commonly known as turban or top snails and there are many species that look very similar (in the hundreds).


You generally know you are dealing with a turban or top snail because the shell will be conical and usually smooth (although sometimes there will be rounded edges). It should look something like a turban or a top. One major exception is the Astraea Snail (from the Family Turbinidae) that has star-like arms.

Once you know you are looking at a turban or top snail, simply look at the operculum (the “trap door” the snail uses to close the shell’s opening) to determine which family it is. If it has a brown and somewhat horny operculum it’s from the family Trochidae; if it has a white operculum it’s from the family Turbinidae.

Snails from both families are algae grazers, but they will not take care of all algae. Grazing snails from these two families feed exclusively on diatoms, dinoflagellates and microalgae, so you need to add other animals to take care of other algae. Consider the following:

  • Cerith Snails
  • Sea Hares
  • Lettuce Slugs
  • Emerald Crabs

All of these animals are effective herbivores, but as Mark Martin, the Director of Marine Ornamental research at Blue Zoo Aquatics says, “Pound for pound, sea hares are the best algae controlling animals available for the home aquarium.” In a large enough system, you should not have to worry about “inking,” but do your research before adding a Sea Hare. The Emerald Crab is a rarity in the crab world, given that it is mostly herbivorous.

Sand Sifting

Saltwater aquaria with sand do best with sand sifting invertebrates to shift and stir the sand. Some of the best choices are:

  • Nassarius Snails
  • Sand Sifting Starfish
  • Tiger Tail Cucumbers

If you have a sand bed, Nassarius Snails are highly recommended. They grow to about an inch in length and are long-lived. Sand Sifting Starfish can also be excellent sand bed cleaners, although some reef enthusiasts choose not to keep them, as they can strip the sand of all edible material (even the good stuff). Despite what you may have heard, the Tiger Tail Sea Cucumber is a great reef inhabitant. It’s an herbivore that literally vacuums up the sand, consumes bacteria and microalgae, and then passes it as sparkling clean substrate. You only need to worry about toxicity if the system is too small (less than 50 gallons), but still do your research.

Detritus Control

Detritus includes left over food, animal waste, dead animals, sheddings from animals, etc. To control detritus, consider the following animals:

  • Bumble Bee Snails
  • Nassarius Snails
  • Cerith Snails
  • Blue Leg Reef Hermit Crabs
  • Scarlet Reef Hermit Crabs
  • Sally Lightfoot Crabs

With a thoughtful combination of the animals listed here, you can have a highly effective clean-up crew for your saltwater aquarium.

My name is James, and I’m in love with aquariums and fish since I was 12 years old. Back then my dad gave me a goldfish, and it’s been 35 years learning about this fascinating hobby. I’ve had some freshwater aquariums, tried my hand with marine tanks for 10 years, and kept some reefs for a while too. Here in the website I try to share some of my knowledge and experiences on fish keeping.


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