How to Remove a Hard Water Line From a Glass Aquarium

Aquariums add an elegant underwater world to your home while providing an interesting hobby for people of all ages. In order to keep your fish happy and healthy, you must maintain a clean, glass aquarium. Over time, hard water can leave a water line on your glass aquarium. Typically not harmful to the fish, the hard water line will cause your aquarium to appear dingy. Common glass cleaners contain ammonia, which can harm fish. Fortunately, you can remove the hard water deposit using a common and inexpensive household item that will not harm your fish.

Things You'll Need

  • Buckets
  • 1/2 distilled white vinegar
  • Spoon
  • Spray bottle
  • Marker
  • Aquarium siphon
  • Lint-free cloths
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Instructions

    • 1

      Pour 1/2 gallon of water in a bucket. Add 1/2 cup of distilled white vinegar and mix with a spoon. Fill a new spray bottle with the mixture. Write "Aquarium Glass Cleaner" on the spray bottle with a marker for future use.

    • 2

      Siphon enough water out of the aquarium -- as you normally would -- so the water does not cover the hard water line.

    • 3

      Dampen a lint-free cloth in the vinegar water. Make sure the cloth is not dripping wet. Even though a little vinegar will not harm your fish, too much vinegar can change the pH balance of the water.

    • 4

      Rub the water line with the damp cloth in a vigorous circular motion. Rinse the cloth in the mixture when it becomes soiled. Continue rubbing the glass with the damp cloth until you have removed all traces of the hard water deposits.

    • 5

      Dampen a clean, lint-free cloth with cool water and wipe the vinegar mixture off the aquarium glass. Dry with a lint-free cloth.

    • 6

      Replace the water you previously removed as you normally would.