How to Mix Saltwater for an Aquarium

Saltwater aquariums require regular water changes with synthetic salt mix. Otherwise toxic chemicals and compounds can build up in the water and impact the health of your fish and plants. You also need to check the salinity of the water before it is added to the tank. It's important to mix the water properly and thoroughly, and to use purified water. You can obtain purified water at a reduced price at your local fish store.

Things You'll Need

  • Purified water
  • Suitable container
  • Aquarium air pump
  • Measuring cup
  • Aquarium salt
  • Large plastic spoon
  • Refractometer or specific gravity meter
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Instructions

    • 1

      Pour purified water into a container that is large enough to account for at least five percent of the volume of the tank to which you are adding water. Aerate the water with an aquarium pump for 24 hours to drive out any excess CO2.

    • 2

      Measure out the correct amount of aquarium salt for your volume of water, according to the manufacturer's instructions. Use a clean measuring cup that is only used for the aquarium.

    • 3

      Add salt to water and stir with a large plastic spoon to mix. Keep stirring until the salt is totally dissolved.

    • 4

      Test the water salinity with a refractometer or specific gravity meter. The specific gravity should measure between 1.020 and 1.026.