Discoloring bathroom shower grout, cleaning?
Hi All. So our shower stall is about 6 months old. The whitish grout is showing signs of darkening toward the bottom area of the stall wall. Almost looks like stains or mildew. Whatever it is, seems to be spreading. Cleaning with bleach seems to have no effect. It doesn't seem to be a stain simply on the surface.
Any ideas what it is or causing it? Don't think any shampoos are doing it.
How might I go about cleaning it? Any heavy duty grout cleaners? I do not believe the grout is sealed.