Soap scum is a layer of white or gray film that covers itself on the bath tile, toilets, shower curtains, bathroom fixtures and bathroom floors. Minerals in the tap water combine with dirt and soap residue in the bathtub, shower or sink to form a film on top of tiled surfaces.
To remove soap scum from the bathtub and tiles, rub the surfaces with a cut lemon. The acid in the lemon breaks down bacteria and dirt found in soap scum. To keep these areas free of soap scum, rinse them thoroughly after each use so there's nowhere for bacteria to grow.