How do I get rid of pink stains in my shower?

Those pink stains are almost certainly Serratia marcescens, a naturally occurring airborne bacteria (not mold) that thrives in warm, humid environments with soap residue and mineral deposits. The good news is it's easy to remove — but it comes back quickly without the right habits.

Removing the Stains

The most effective DIY solution is a paste of baking soda and dish soap scrubbed directly onto the stained areas, left for 10 minutes, then rinsed. For tougher buildup, a diluted bleach solution (1 part bleach to 10 parts water) sprayed on and left for 5-10 minutes will kill the bacteria and lift the staining. Always wear gloves and ensure good ventilation when using bleach. Avoid mixing bleach with any other cleaners — especially anything ammonia-based.

Protecting Your Grout and Surfaces

Be mindful of what you're scrubbing. On natural stone tile (marble, travertine, limestone), avoid bleach entirely as it can etch and damage the surface — use a pH-neutral cleaner instead. On ceramic or porcelain tile, bleach is generally safe. If your grout is old or unsealed, the bacteria can penetrate deeper and become harder to remove over time.

Keeping It From Coming Back

This is the real battle. Serratia marcescens returns fast — sometimes within days — if conditions are right. The most effective prevention habits are running your exhaust fan during and for 15-20 minutes after every shower, wiping down wet surfaces after use, and doing a weekly spray-down with a diluted bleach or bathroom disinfectant spray. Re-sealing your grout annually also makes surfaces much less hospitable to bacteria.

If you're noticing persistent pink staining despite regular cleaning, it may be a sign of a ventilation problem — an undersized or failing exhaust fan that's leaving too much moisture in the air. That's worth addressing, as chronic moisture also leads to more serious issues like mold behind walls and deteriorating grout.