How to Care for Aquarium Crabs

Crabs function as a "cleaner crew" in saltwater aquariums, eating leftover food and algae within an aquarium. Hermit crabs, arrow crabs and emerald crabs live well in most saltwater and reef aquariums, as long as certain care and feeding requirements are met.

Things You'll Need

  • Rocks
  • Substrate
  • Food
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Instructions

    • 1

      Maintain good water quality. All marine life needs chlorine-free, ammonia-free saltwater which is low in nitrates and nitrites. Test your water frequently and perform routine bi-weekly water changes.

    • 2

      Provide hiding spaces. Crabs need rock crevices and caves. Some species like a deep substrate (the sand or gravel at the bottom of an aquarium) into which they can burrow.

    • 3

      Feed your crabs. As Saltwater Aquarium Guide explains, crabs scavenge leftovers. However, you need to make sure they get enough food--especially if you want to keep them from going after your fish and corals. Tiny crabs appreciate a "marine snow" type of food (zooplankton and phytoplankton) or rotifers. Medium crabs can eat krill or brine shrimp. Larger crabs will take cut bait fish or shrimp. If you do not have a lot of algae, provide seaweed supplements.