How to Fix Hard Water in Tropical Fish Tanks

A fish tank that contains hard water buildup will usually also experience abnormally high pH levels. Hard water results when too much calcium and magnesium salts present themselves in the water. This scenario usually occurs with the use of treated tap water. When a fish tank contains a high concentration of hard water, it makes it very difficult to control the pH levels. A pH that remains too low or too high can eventually sicken your fish. A water-softening pillow can help control hard water levels.

Things You'll Need

  • Water-softening pillow
  • Iodized salt
  • Small bowl
  • Airtight container
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Instructions

    • 1

      Remove the water-softening pillow from its packaging. Place the pillow either in the filter or in the tank itself. The water-softening pillow will work best if used directly in the filter.

    • 2

      Allow the water-softening pillow to remain in the tank of filter for at least 48 hours. After 48 hours, remove the pillow and recharge it.

    • 3

      Mix 3 tbsp. of iodized salt and 7 oz. of water in a small bowl. Set the water-softening pillow in the bowl, completely covering it with the solution.

    • 4

      Leave the pillow in the solution for two hours. After that, place the water-softener pillow back in the tank or filter. Recharge again after 48 hours.

    • 5

      Store the saltwater recharging solution in an airtight container until you need to use it again in 48 hours. Mix up a new batch of recharging solution after four recharges.