- 1). Kill the mold with a mixture of one part bleach to ten parts water. This will also lighten the blackened surface. Apply the bleach mixture with a toothbrush on a small, hidden part of the tile and grout to make sure the bleach will not discolor the tile. Once the mold has gone, rinse the area and allow it to dry. If you see no discoloration, scrub the rest of the wall.
- 2). If you observe discoloration when you test the bleach mixture on the tile, try using a mixture of less bleach and more water. If the weaker mixture still causes discoloration, don't use bleach on any further tiles.
- 3). If the stain still persists, mix of vinegar and water or make a paste of baking soda and water. Spread it over the stained area and allow it to sit for several minutes. Rub the mixture into the stain with a cloth.
- 4). Clean the surface with a mild detergent or soap, such as dish liquid or a bar of bath soap. Lather a cloth and wipe the area clean.
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