What is the pink or black stuff in my toilet and shower?
Usually, this pinkish film appears during and after new construction or remodeling activities. The dirt and dust stirred up from the work probably contains Serratia bacteria. Once airborne, the bacteria seek moist environments to proliferate. Some people have even noted the pink residue in their pet’s water bowl, which causes no apparent harm and can be easily cleaned off. Others have indicated that their experience with this nuisance occurs during a time of year that their windows are open for the majority of the day. These airborne bacteria can come from any number of naturally occurring sources, and the condition can be further aggravated if customers remove the chlorine from their water by way of an activated carbon filter.
