How to Add Salt to a Fresh Water Tank

Aquarium hobbyists have been adding salt to freshwater tanks for decades now. Salt can be used as a natural medicine to kill parasites and treat some other fish diseases, restore the sodium and chloride ions into the water that sick fish need to recover, and may also help to prevent the fishes' intake of dangerous toxins such as nitrites. In addition, live-bearing fish and other brackish water species come from areas in the world where there is a greater content of salt in freshwater. These fish will gladly welcome the addition of salt into their aquarium.

Things You'll Need

  • Small container
  • Aquarium salt
  • Tablespoon
Show More

Instructions

    • 1

      Purchase aquarium salt from your local pet store. You can also use store-bought rock salt or Kosher salt, but only if the product contains no additives such as iodine or potassium.

    • 2

      Use a clean small container to scoop some water out of your fish tank. This water will be used to dissolve the salt before pouring it into your aquarium.

    • 3

      Add 1 tbsp. aquarium salt to the small container of water for every 5 gallons of your fish tank. For example, if you have a 20-gallon fish tank, you would use 4 tbsp. salt.

    • 4

      Allow five minutes for the salt to dissolve in the small container of water.

    • 5

      Pour the water from the small container back into your aquarium. Do this slowly, so you don't stress your fish. The water will mix within seconds.