Hard water, bacteria, and mildew can cause those unsightly rings.

Add Yahoo as a preferred source to see more of our stories on Google. Getty Images Dealing with hard water stains in your toilet? These left behind mineral deposits can make your toilet look ...

If toilet bowl rings seem to be a constant in your bathroom, it's probably not from cleaning, or lack there of. Hard water is a common cause of these stubborn stains since minerals deposit on the ...

Cleaning the toilet: It's the one chore that no one likes to do, but must be done regularly to prevent stains. Cleaning the toilet bowl isn't the most pleasant household chore on the list, but ...