How to Remove White Stains From a Black Toilet

Turn on the exhaust fan in the bathroom and open a window to circulate the air.

Turn off your toilet's water supply by turning the valve -- usually located on the wall just behind the toilet -- to the right until you cannot turn it anymore.

Remove the water from the toilet. Flush it once, then plunge the toilet to force the remaining water down the drain.

Hold the brush-end of your toilet scrubber over the bowl.

Pour a scale-removing product that contains diluted phosphoric, hydrochloric, hydroxyacetic or muriatic acid, but not bleach, slowly over the bristles until they are thoroughly wet.

Set the bottle down on the folded newspaper sheets to prevent runoff from touching the floor.

Scrub the entire surface of the toilet bowl with the toilet scrubber until the white stains are gone. Scrub back and forth with slow, steady strokes. Pay close attention to the area just under the bowl's rim and any visible stains. Scale remover contains strong acids that may damage the surrounding fixtures or your skin if it splashes and splatters. Clean any accidental splatters up immediately with a wet rag. Re-apply the scale remover to the toilet scrubber as necessary.

Turn the water valve back on by turning it to the left until it stops turning.

Flush the toilet twice.

Rinse the scrubber and clean-up rag thoroughly in the sink.