The majority of us understand by now to be afraid of black mold, but pink mold is another story. The pink bacteria that builds up on the grout between your bathtub tiles is known scientifically as Serratia marcescens, and it feeds on fatty substances such as soap scum. Pink mold can cause respiratory tract infections and infection of wounds, so it’s in your best interest to give your shower a great scrub as soon as you see it beginning to form.
Mix 1/2 cup of baking soda with 1 tablespoon of dishwashing liquid. Add enough water to make a runny paste.
Dip a nylon-bristle scrub brush to the baking soda paste and wash your bathtub tile, paying particular attention to the grout between the tiles. Rinse the bathtub thoroughly after scrubbing.
Fill a spray bottle halfway with white vinegar or chlorine bleach. Add warm water to fill it up the rest of the way.
Spray the tile and grout using the bleach or vinegar spray and permit it to soak for 10 minutes. Scrub the bathtub again with the brush before rinsing thoroughly with water.
Dry the bathtub by wiping it down with a clean towel.
Keep the bleach or vinegar spray in your toilet and also spray on the shower after each use to assist in preventing soap-scum buildup and mold regrowth.