If you're referring to a ring-shaped stain or deposit inside the toilet bowl, commonly known as a "toilet bowl ring," you can try the following methods to remove it:
1. Toilet bowl cleaner: Start by using a commercial toilet bowl cleaner that specifically targets tough stains. Apply the cleaner to the affected area and let it sit for the recommended amount of time. Then, scrub the ring with a toilet brush, paying extra attention to the stained area. Flush the toilet to rinse away the cleaner and inspect the results. Repeat if necessary.
2. Baking soda and vinegar: Sprinkle baking soda around the ring, ensuring it covers the stained area. Pour vinegar over the baking soda, and it will create a fizzing reaction. Let the mixture sit for a few minutes, then scrub the ring with a toilet brush. Flush the toilet to rinse.
3. Pumice stone: Wet the pumice stone and gently scrub the ring. Make sure to keep both the stone and the toilet bowl wet while using it. Scrub with light pressure to avoid scratching the toilet bowl surface. Rinse the toilet bowl thoroughly after using the pumice stone.
4. Coca-Cola: Pour a can of Coca-Cola into the toilet bowl, ensuring it covers the ring. Let it sit for several hours or overnight. The phosphoric acid in the Coca-Cola can help dissolve the stains. Afterward, scrub the ring with a toilet brush and flush the toilet.
5. Bleach: If the above methods don't work, you can try using bleach as a last resort. Put on rubber gloves and ensure the bathroom is well-ventilated. Pour a small amount of bleach directly onto the ring and let it sit for a while. Scrub the ring with a toilet brush and flush the toilet thoroughly to rinse away the bleach.
Remember to read and follow the instructions and safety precautions on the cleaning products you use. It's essential to use proper ventilation and wear gloves when using bleach or any other harsh chemicals. If the ring persists despite your efforts, it might be necessary to seek professional assistance or consider replacing the toilet bowl.