What Keeps the Sand Clean in a Saltwater Aquarium?

Saltwater fish and other marine creatures, pass metabolic waste which fuels algae growth, into their aquarium water. Nuisance algae often grow on the sea sand in these aquariums and detract from the aesthetic appeal of the tank. Living invertebrate creatures, such as snails and crabs will graze algae and detritus from the surface and within the substrate in marine aquariums. By combining different species in a single tank, you can ensure that the sand will stay clean.

  1. Grazing Snails

    • Turbo snails are highly efficient at cleaning sand, but large specimens will dislodge rocks. Only add turbo snails to your aquarium after a few months to make sure that there is enough food for them. Asterea snails will forage on hair algae that are growing on the sand. These 1-inch long snails are a good addition to your clean-up crew, but are unable to right themselves, if they topple over. Trochus snails also remain small, as do nerite snails. All these snail species will target algae and detritus that is on the surface of the sand bed.

    Sifting Snails

    • Nassarius snails are an important addition to your clean-up crew because they bury themselves beneath the sand and feed on detritus and organic material that is decomposing out of sight. These interesting snails agitate the sand bed by continually sifting through it, which moves the detritus to the surface where other snail species can feed. Nassarius snails prefer a sand bed with a depth of at least 4 inches and should not be added to your aquarium until several months have passed, or they will not find enough food.

    Crabs

    • Red-legged hermit crabs stay small and are excellent scavengers in a saltwater aquarium. These hardy little crabs feed on all of the commonly found algae species, including hair algae and will also eat left-over fish food. The blue-legged hermit crab will eat anything edible from the substrate, but as with the red-legged hermit crab, must be supplied with empty shells as it grows so it can move into a more spacious home. Sally Lightfoot crabs constantly eat detritus and algae from the sand bed and are a valuable addition to your marine aquarium. Emerald green crabs are one of the few species that eat bubble algae.

    Shrimps and Starfish

    • Cleaner shrimps and coral banded shrimps make excellent work of scavenging for leftover food on the aquarium substrate. These shrimps do not bother living corals and can be safely housed in saltwater aquariums that contain anemones and both hard and soft corals. The true peppermint shrimp will also keep your sand free of debris and detritus, as will the sand sifting starfish. These starfish grow up to 12 inches though and need a deep sand bed.