Algae and other contaminants may accumulate in your toilet water tank. Also, minerals such as lime and calcium can build up and corrode certain parts of your toilet water tank, so it is important to clean your tank periodically. You can also take preventive care of your tanks by placing bleach tablets that are designed for toilets in the toilet tank.
Shut off your toilet's water supply. Turn the valve on the water line outside your toilet clockwise 90 degrees to cut off the water supply.
Flush the toilet to remove the existing water from the tank.
Fill a spray bottle with vinegar, then spray down the inside of the tank. Or, pour vinegar into the tank, soaking the walls of the tank. Bleach can also be used to clean your toilet tank; however, vinegar is less harmful if you splash it on your clothes or skin. Vinegar also removes lime deposits from the tank in addition to algae growth.
Scrub the inside of the toilet tank with a scrub brush to remove difficult algae and other deposits.
Turn the water supply to the toilet back on by turning the valve counterclockwise 90 degrees. Flush the toilet a couple times to remove the residual vinegar as vinegar is acidic and can corrode the metal in your toilet tank if it's not flushed out.