How to Soften the Water in a Freshwater Tank

Several types of fish, including rosy barbs and cardinal tetras, prefer soft water to hard water. Water hardness refers to the amount of calcium and magnesium in the water. Unfortunately, we can't always choose the hardness of our water, so you may need to soften the water in your freshwater tank. Many homes are equipped with a water softening unit that uses a method called "ion replacement" to replace calcium and magnesium ions with sodium ions. Your fish won't care for the sodium any more than the hard water. Using aged water is an easy solution for fish.

Things You'll Need

  • 1 gallon peat moss
  • Stock pot
  • Pillow case
  • 5-gallon bucket
  • Air pump
Show More

Instructions

    • 1

      Boil the peat moss in a stock pot of water until the peat begins to sink.

    • 2

      Place a pillow case inside a bucket and drape the open end over the bucket edges.

    • 3

      Pour the peat mixture into the bucket, using the pillow case to strain the peat from the water. Tie the pillow case closed and leave it in the bucket.

    • 4

      Fill the bucket to the top with water.

    • 5

      Aerate the water and peat moss for one to two weeks with an air pump, such as the pump you use for your fish tank.

    • 6

      Pour the aged water into your freshwater tank; make another batch to use later when you make partial water changes.