I have a bathroom in the middle of my house (no outside walls) and we put in an extra strong fan to suck out the steam, and it still gets mold in the shower, ceiling and wall joints. We are also on a septic system, so I don’t like to use the chemicals if I can avoid it. I finally found an environmentally friendly, cheap solution. Mix two cups of hot water, one tablespoon of borax and two tablespoons of vinegar in a spray bottle. Shake and spray on. I used a toothbrush (to scrub) and rag (to catch the drips running down the walls) and the mold is gone. I also have started to use vinegar to clean my toilet.
Remove mold from bathtubs Mix 4 or 5 drops of clorox bleach, 2 tsps of dish detergent and 1 tsp of washing liquid. Then apply this mixture on the area with mold. Let stay for some time then wash away.. it keeps mold from coming back for at least 5 days
Use two cups and let sit overnight to do the initial cleaning. Then just use a bit once a week to keep it up.