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How to Make Salt Water for Hermit Crabs

| Updated September 26, 2017

Things You'll Need

  • Clean plastic bucket

  • 1 gallon tap water

  • Aquarium tap water conditioner

  • Ocean salt from a pet store

  • Mixing spoon

Hermit crabs may be used for the cleaning of saltwater aquariums or as pets. They are adaptable creatures but require saltwater in order to remain healthy. Hermit crabs use the same salinity of saltwater as saltwater fish. This can be purchased or made at home using ocean salt from a pet store. Table salt is not an acceptable alternative to maintain your hermit crab's health.

Pour the tap water into the mixing bucket. To this water add the aquarium conditioner. This isolates the chlorine and chloramine in the tap water making it safe for use in your aquarium.

Pour exactly 1/2 cup sea salt into the water and mix it thoroughly. The water will remain cloudy for a while until all the sea salt dissolves.

Allow the water to reach room temperature before adding it to your aquarium. This will also give the aquarium water conditioner time to remove the last of the chemicals in the tap water which would be harmful to your hermit crab. After two to three hours, when the water has reached room temperature, it can be poured into the aquarium.


  • Premixed salt water can be purchased from specialty fish stores which does not need to be treated before use in your aquarium.


  • Avoid adding plain tap water to your aquarium. Treated tap water is much safer for hermit crabs and fish.