Colors in your shower

If you have ever scrubbed a pink or salmon-colored film off your shower walls, grout, or curtain and wondered whether you were looking at mold, you are not alone. I get this question constantly, from homeowners, from dealers, from people who corner me at trade shows because they heard I know water. The short answer is that it is almost never mold. It is bacteria, and once you understand what it wants, it becomes a lot easier to manage.
For most households, though, this is simply a matter of chemistry and habit. Break up the biofilm, disinfect, dry your surfaces, and stay ahead of it weekly. Do that, and the pink residue stops being a recurring nuisance and becomes a rare annoyance you handle in five minutes.