If you have hard water, you may have limescale in your toilet. Limescale refers to solidified mineral deposits. Water that passes through softer rock such as limestone can dissolve minerals, rendering the water "hard." When hard water contacts other surfaces it can leave these dissolved minerals behind in the form of limescale. Try using household vinegar to break up the limescale deposits in your toilet.
How it Works
Vinegar works as a cleaner because it contains acetic acid. Because limescale is alkaline, vinegar can be used to combat limescale deposits. The pH scale spans from zero to 14.0, with zero being the most acidic value and 14.0 being the most alkaline. Vinegar has a pH of about 2.4, making it an effective natural acidic cleaner.
Benefits of Vinegar
Consider the benefits of vinegar as a cleaning product. Many commercially available limescale removers contain sulphamic acid, which is toxic if inhaled or ingested. Vinegar is very cost effective, as well as being widely available for purchase. It is also safe for septic systems and better for the environment than chemical cleaners.
Paper Towel Method
Scoop out enough toilet water to expose the limescale. Soak paper towels in vinegar and apply them to the areas you want to clean. Leave them for several hours to allow the acid in the vinegar to dissolve the limescale. Remove the paper towels and dispose of them in the garbage so that they do not plug the toilet. Scrub the toilet with a toilet brush and flush.
Long Soak Method
If you cannot remove enough toilet water to expose all of the limescale to be cleaned, try adding two cups of vinegar directly to the toilet water. This dilutes the strength of the vinegar, so the toilet will have to be left unused overnight for the vinegar to effectively soak into the limescale.