1. Cleaning Solutions: Start by using a specialized bathroom cleaner or a mixture of bleach and water. Apply the solution to the affected area and let it sit for a few minutes. Scrub the stain gently with a toilet brush or a sponge, then rinse thoroughly with water. Repeat the process if necessary.
2. Vinegar: Vinegar is known for its natural cleaning properties. Fill a spray bottle with white vinegar and spray it onto the black circle. Allow it to sit for a few minutes, then scrub and rinse. The acidic nature of vinegar helps dissolve mineral deposits and kill mold and mildew.
3. Baking Soda: Another effective method is to create a paste by mixing baking soda with water. Apply the paste to the black circle, scrub gently, and rinse. Baking soda’s abrasive texture helps remove stains and eliminate odors.

Prevention for a Clean and White Bathroom: