What causes the pink stain on bathroom fixtures?
The reddish-pink stain or residue that is frequently found around bathroom sinks, shower stalls, and pets’ water bowls, is not by the water supply but by naturally occurring airborne bacteria that produce a reddish pigment. There are numerous bacteria in the environment that find their way onto bathroom and kitchen fixtures. Most do not cause disease. These bacteria are found in soil, food, and on animals, and they may become airborne because of construction or wind. It is not uncommon to find the pinkish film appearing after new construction or remodeling activities.