How to Remove Calcium Buildup on Fish Tanks

Calcium buildup is caused by mineral deposits from hard water. Buildup in a fish tank manifests as white streaks or spots on the walls, usually around the water line. As the water in the tank evaporates, the minerals adhere to the glass, creating calcium deposits. The longer you wait between tank cleanings, the harder it will be to remove the buildups. However, even the toughest calcium buildup can be removed with the right tools.

Things You'll Need

  • Large container or second tank
  • White vinegar
  • Spray bottle
  • Paper towels or sponge
  • Tank scraper
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Instructions

    • 1

      Put your fish in another fish tank or large container filled with water, ensuring that the temperature and other conditions of their temporary home are similar to their usual environment. Empty all the water from the tank and remove all rocks and other decorations.

    • 2

      Combine two cups water with one cup of white vinegar in the spray bottle. Shake well.

    • 3

      Spray the walls of the tank with the vinegar solution and let it sit for three minutes. Wipe down with paper towels or sponge. If necessary, scrub the areas with calcium buildup. Repeat as necessary.

    • 4

      Use the tank scraper to get rid of any remaining calcium.

    • 5

      Wash all rocks and tank decorations in a solution of white vinegar and water.

    • 6

      Thoroughly rinse all decorations and the walls of the tank with clean water. Test the pH level in the tank to ensure that the vinegar has been completely rinsed out. Replace rocks and decorations, refill with water, and return the fish to the tank.