How to clean black water stains in a toilet

Updated April 17, 2017

Black stains in your toilet bowl are the result of hard water containing calcium and limestone deposits. As these mineral deposits accumulate, unsightly black rings form that are difficult to remove. Despite how clean it actually is, stains make your toilet appear filthy. Read on to find out how you can eliminate these unattractive water stains.

Put on the protective face mask and rubber gloves. Open any windows or doors in your bathroom to promote ventilation.

Pour two cups of liquid bleach into your toilet. Using the plastic toilet brush, mix the bleach into the toilet water and lightly scrub the stains to loosen the deposit build-up. Leave the bleach in the water for 30 minutes.

Flush your toilet 2-3 times to completely eliminate the bleach. Sprinkle Borax Powder over the stains. Allow the powder to sit on the stains for one to-12 hours, depending on their intensity.

Using the Pumie Stick, gently scrub the discolourations in small, circular motions. Repeat as necessary until the black water stains disappear.


Borax Powder and Pumie Sticks can be found at your local hardware or home improvement store. Bleach, rubber gloves and protective face masks are available from the grocery or chemist.


Bleach and Borax Powder are powerful and hazardous cleaning agents. Don't let them touch your skin, hair, or clothing-- if this happens accidentally, immediately rinse the affected area with cold water. Seek medical help if necessary. DO NOT mix the bleach and Borax Powder. This will create highly toxic and potentially deadly fumes. If you begin to feel faint or dizzy from the fumes of the cleaning products, leave the room for some fresh air. Return only when you feel normal again.

Things You'll Need

  • Liquid Chlorine Bleach
  • Plastic Toilet Brush
  • Pumice Stone (also called a "Pumie Stick")
  • Borax Powder
  • Rubber Gloves
  • Protective Face Mask
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About the Author

Hailing from San Francisco, Arwen Petty is a market development editor for international academic publisher Cengage Learning Inc. Her work has appeared in "[X]Press Magazine," "AMP Magazine" and on She holds a Bachelor of Arts in journalism from San Francisco State University.