Eli5 What is the pink buildup in showers?

Question

I just don’t understand where it comes from and how it builds up.

In: 21

Answer 1

It’s a bacteria, most likely Serratia marcescens, which is airborne so it’s basically everywhere. It builds up as it grows in the lingering moisture of the environment (your shower). It’s also mostly harmless (so touching it while showering or cleaning usually won’t cause problems; my understanding is it’s fairly rare that it causes infection). Spray it with a 1:1 ratio of bleach and water to clean it. 🙂