How to Change the Water in a Brackish Aquarium

To keep your brackish water aquarium clean and chemically balanced you need to periodically change out part of the water. A brackish water aquarium has less salt then a saltwater aquarium and emulates the water that can be found in the mouths of rivers where the river meets the sea.

Things You'll Need

  • Bucket
  • Water
  • Chemical Neutralizer
  • Siphon hose
  • Salt
  • Bucket to store salt water
  • Hydrometer
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Instructions

    • 1

      Purchase a bag of salt for a saltwater aquarium. You can purchase table salt, though it is not recommended, rock salt, aquarium and marine salt. Your best bet is to purchase aquarium or marine salt, as it is made specifically for fish. However, if you cannot find aquarium or marine salt, you can use table salt, rock salt or salt pellets in an emergency.

    • 2

      Mix salt with tap water. Mix one tablespoon of salt to five gallons of tap water. Allow the water to sit overnight in the same room as the tank so the water temperature matches. Do not cover the water. For best results, purchase spring water and mix the salt with the spring water. This way, you do not need to worry about chlorine, fluoride and other additives in city water.

    • 3

      Use a hydrometer to get the salt water to the proper density. Your aquarium store can tell you what level is appropriate for the brackish fish you buy. If you do not have a hydrometer, take a sample of the water to the fish supply store and ask them to check it for you.

    • 4

      Remove 20 percent of the water in the fish tank. Do this by siphoning the water, if you have a siphon, or a bucket.

    • 5

      Replace the water you have removed with the brackish water. Do this once every three to four weeks for best results.