A pink film or residue on bathroom and kitchen surfaces does not indicate a problem with water quality. It is likely the result of airborne bacteria found in moist areas around the home such as toilet bowls, shower heads, sink drains, tiles and, pet bowls. The bacteria that causes this pink film is most likely Serratia Marcesens, which is found naturally in soil, food, and on animals, though other bacterium can cause similar residues. Serratia M., which produce a characteristic red pigment, thrive on moisture, dust, and phosphates and need very little organic material to survive.