Use a Pumice Stone for Extra Hard Black Rings
They are softer than porcelain but stronger than mineral deposits, making it the perfect solution to eliminate rings. Cleaning toilet rings with a pumice stone might require you some hard scrubbing. However, you can be sure that no waterline is strong enough to endure it.
Vinegar and baking soda: Add 1 or 2 cups of vinegar to the toilet bowl along with a few sprinkles of baking soda. Swish the solution around the bowl with your brush for a few minutes and then let it sit for about 15 minutes. Scrub the stains with your brush (or pumice stone).
Because water deposits build-up under a toilet's rim, it can take only 24-48 hours for colonies to start breeding. As it grows, you will see what looks like black debris or rings inside the bowl. This can cause respiratory problems for people as the mold and mildew release tiny spores into the air.
Black mold can be found in your toilet bowl or tank when you have been away for even a few short days on vacation. It can also happen if there has been waste left in the bowl for a while. Since humidity and dark places are where mold thrives, your toilet bowl and tank are prime breeding ground for it.
To safely and inexpensively clean your toilet bowls, pour a generous glug of vinegar, followed by a heavy sprinkling of baking soda, into the bowl. While the mixture is bubbling up, scrub the bowl (get under the rim, too). Let it soak for 30 minutes and flush. That's it.
For particularly stained or foul tanks, turn the water valve off, flush the toilet until the tank is empty, and fill the tank with just vinegar (no water), letting it sit overnight.
If the clog is minor, pour all of the baking soda measured into the toilet bowl. If the clog is severe, pour up to one-half a cup of baking soda in the toilet. Remember to use equal parts of vinegar and baking soda. So, for every one cup of baking soda you use, use one cup of vinegar.
To that end, when it comes to using baking soda for your toilet, there are two primary purposes: using baking soda to clean and remove stains, and using baking soda to unclog your toilet.
White vinegar has 5 percent acidity; while cleaning vinegar, on the other hand, has 6 percent. Although it's only a one percent difference in acidity, it actually results in cleaning vinegar being 20 percent stronger than white vinegar.
Vinegar is a great toilet cleaning solution. Not only is it free of chemicals and naturally antibacterial, it's also an acid, so it will remove minor lime and calcium deposits. All you need to do is pour a couple cups of vinegar in your tank and let it sit for an hour or so, then scrub and flush to rinse.
Mold comes in a lot of colors. Black toilet mold is the most common color that forms a “ring” in your toilet. This ring can also be from green mold or grey mold. Orange or pinkish slimy mold can develop around the toilet bowl at the spot where the top of the water sits in the bowl.
Black rings form in the toilet bowl due to hard water. Hard water has minerals that accumulate. When the minerals form in the toilet, they may appear brown, gray or black in color. Toilet bowl rings that appear dark red in color indicate that too much iron is in the water.