Reef-Safe Sand Sifters

Mechanical filtration and vacuuming the substrate can help remove detritus and uneaten food in a saltwater aquarium. However, one of the great advantages that marine aquariums have over freshwater aquariums is that there are all sorts of natural critters in the ocean that you can put in your saltwater aquarium that will do a majority of the tank cleaning and maintenance for you.

Sand sifters keep the substrate in your aquarium clean by sifting through the sand, removing detritus, uneaten food and other tank debris. Many of the animals which sift sand can also harm or destroy other life in your tank so you must be careful to choose the right critters for this job. Reef-safe sand sifters do it without harming fish, corals and other invertebrates in your reef tank.

Reef-safe Sand Sifters process the substrate surface, consuming algae, detritus ​and uneaten food without adversely affecting other organisms in the aquarium. 

When setting up your saltwater aquarium and choosing your substrate, if you are planning to include sand sifting fish, be sure to select a substrate with a small enough grain size (0.5-1.7 mm grain size or sugar-sized sand) that the fish will be able process it through their mouth and especially the gills. Do not use large grained sand, crushed coral or large size aragonite as the sand sifters will not be able to process this material without injuring themselves.

  • 01 of 05


    tunart/E+/Getty Images

    Most marine crabs are well known for having voracious appetites, consuming detritus, uneaten food and carrion in saltwater aquariums. Unfortunately, most crabs will eat just about anything else in your tank, including corals, fish and other invertebrates.

    There are a number of reef-safe crabs which do not consume the "good" stuff in your reef tank. Some of the Crabs which sift through and stir the surface of the tank substrate and are considered to be reef-safe are:

    Caution should be taken when placing crabs in your reef tank. Most crabs are not reef-safe as they will consume just about anything they come across. Even with the "reef tank safe" crabs, you will occasionally come across a "rebel" that does not leave corals or invertebrates alone.

  • 02 of 05

    Hermit Crabs

    Hermit Crabs are great sand stirrers. Reef-safe Hermit Crabs spend all of their time looking for and consuming algae and detritus. Smaller species Hermit Crabs are preferred over the larger species, as they will not disturb the tank environment.

  • 03 of 05


    Some snails spend all of their time either on the glass, or on the rocks in a saltwater aquarium, avoiding the sand substrate. Why? One reason may be that some snails cannot extend their foot far enough from their shell to turn themselves over if they end up on their "back".

    Here are some great reef-safe sand sifting snails which not only consume the detritus and algae on your substrate but can flip over when they need to, avoiding being eaten or starving.​

  • 04 of 05

    Sea Cucumbers

    Sea Cucumbers are arguably the ugliest things you can put in your saltwater aquarium. On the other hand, a number of them do an excellent job of cleaning the substrate in a saltwater aquarium, stirring the sand surface as they inch along at glacial speed.

    Many Sea Cucumbers will not only consume detritus and uneaten food, but also snails and other substrate dwelling critters, making them unsuitable for reef aquariums.

    Continue to 5 of 5 below.
  • 05 of 05

    Sand Sifting Gobies

    Gobies are among the most beautiful and entertaining fish found in saltwater aquariums. Some (not all) Gobies process the sand substrate in an aquarium in search for food (algae and detritus). Sand ​sifting Gobies literally "eat" sand, removing the algae and detritus, then either spit the sand out of their mouths or eject it through their gills.