Black bits at the bottom of the toilet is a cheap and easy way to stop black mold.
If you allow the acid to sit in the toilet tank for more than 10 minutes, it will cause the metal in your tank to oxidize.
Black build up in a home toilet tank is most common in areas with a large amount of water.The iron or manganese in the water causes the black-brown gunk in your toilet tank.When it comes to cleaning the black build up in a home toilet tank, it's best to use a liquid of vino.
Use a scrub brush to remove the black build up.This step may require vigorous scrubbing if the black build up has been there for a long time.
Black build up is left in the toilet tank.If you notice any remaining, continue to scrub at it.