4 Reef Safe Algae Eaters to Keep Your Tank Clean

Reef Tank Safe Rock and Glass Cleaners

sea snail

Vedat Zafer / EyeEm / Getty Images

Some aquarium critters spend all of their time sifting through sand, looking for food. Rock and glass cleaners spend their time browsing for algae on the aquarium walls and rocks, preferring to avoid the substrate. Reef safe algae eaters do their foraging without destroying your corals or other tank inhabitants.

  • 01 of 04

    Reef Safe Hermit Crabs

    Hermit crab - Asia, Maldives, Baa Atoll, Kunfunadhoo (Soneva Fushi)
    Frank Krahmer/Photographer's Choice RF/Getty Images

    Reef safe hermit crab species survive almost solely on a diet of algae and detritus. They spend all of their time crawling over the rocks and substrate in your tank. Being smaller in size, they won't rearrange your tank's "furniture."

    Dwarf Blue Leg Hermit Crab (Clibanarius tricolor) grows to a size of about 1 inch as it eats all kinds of algae, including red slime algae.

    Dwarf Red Tip Hermit Crab (Clibanarius sp.) eats many kinds of algae, including red slime algae (cyanobacteria) and sifts the sand.

    Dwarf Yellow Tip Hermit Crab (Clibanarius sp.) is another small variety (1 inch), which allows it to get into all of the nooks and crannies in a reef tank.

    Dwarf Zebra Hermit Crab (Calcinus laevimanus) has an enlarged left claw (hence its nickname "left-handed hermit crab"), which it uses to repel its enemies by holding the claw across the front of its shell like a shield. In the wild, this hermit crab is usually found inside the reef, hiding under rocks by day and out foraging for food at night.

    Electric Blue Hermit Crab (Calcinus elegans) has bright blue legs with black banding and antennae of bright orange. Both claws are brownish-green in color and nearly equal in size. This crab consumes all types of algae, including red slime algae.

    Electric Orange Hermit Crab (Calcinus sp.) is endemic to Hawaii, has bright orange legs, and unusually blue eyes. It grows to about 2 inches and eats detritus, uneaten food, and many kinds of algae. It also sifts the sand.

    Halloween Hermit Crab (Ciliopagurus strigatus) has a body and legs that are bright orange with red banding. It grows to about 1 1/2 inches in size. It consumes many kinds of algae, including red slime algae.

    Scarlet Reef Hermit Crab (Paguristes cadenati) has red legs and a yellow face and grows to about 1 1/2 inches in size.

  • 02 of 04

    Reef Safe Snails

    Atlantic Moon Snail (Neverita duplicata) / Barrett & MacKay / All Canada Photos / Getty Images
    Barrett & MacKay / All Canada Photos / Getty Images

    Some species of snails cannot turn themselves over if they fall on their backs. These species greatly prefer to spend their time on the rocks and glass in your tank, rather than on the substrate. These snails are herbivores and will do a great job of cleaning your live rock and tank glass.

    Chestnut Cowries (Neobernaya spadicea) are herbivorous snails that require plenty of diatom and microalgae to survive. If this animal runs out of algae, it will slowly die of starvation.

    Margarita Snail (Margarites pupillus) eat a lot and will die if they run out of food, so great care should be taken to avoid overstocking the aquarium with these animals. They are a species of snail that can right themselves if they fall on their shell on the substrate.

    Nerite Snails (Neritina sp.) come in a variety of shell sizes and markings and are very sensitive to copper and nitrate in the water.

    Banded Trochus Snails (Trochus sp.) grow to about 3 inches in size and consume cyanobacteria and diatoms from rocks, aquarium walls, and the substrate. They do not eat macroalgae. Unlike most snails common to the reef aquarium, the banded trochus snail can right itself when knocked over.

    Mexican Turbo Snails (Turbo fluctuosa) grow to about 6 inches in size and require plenty of diatoms and microalgae to survive. They will also consume hair algae off the live rock and aquarium glass. 

    Zebra Turbo Snails (Turbo sp.) grow to about 2 inches in size and also require plenty of diatom and microalgae to survive.

  • 03 of 04

    Reef Safe Blennies

    Rock Blenny (Salarias fasciatus).. Also known as Lawnmower Blenny, Jeweled Rockskipper and Jeweled Blenny. Tropical marine reef fish found mostly perched on rock. Very popular algae eating blenny. Dist. Indo-Pacific Against white background.
    Martin Harvey / Getty Images

    These blennies are herbivores and will spend all of their time eating the algae on your live rock and tank glass.

  • 04 of 04

    Reef Safe Tangs and Surgeonfish

    John Di Genua's Pacific Blue Tang
    John Di Genua

    Surgeonfish make great reef tank glass and rock cleaners. Being herbivores, they eat only algae and leave your corals alone. However, some tangs can get too large for small tanks.

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  1. Blue Tang Surgeonfish. Georgia Aquarium, 2020