I noticed this brownish almost black stain on the grout in the shower floor. I assume it's mold. It's a dark line within the grout. I used bleach which removes it. It eventually comes back. I read that because grout is porous, bleach won't penetrate into the grout and only removes mold on the surface.
I read that hydrogen peroxide and vinegar are good solutions that will penetrate the grout and remove the mold. I put vinegar and allowed it to sit for one hour and then cleaned. I did the same with hydrogen peroxide. However, none of these two household solutions did anything. I'm not sure what else to try? Vinegar and hydrogen peroxide should have removed the black stain. Any other tips?
I read that hydrogen peroxide and vinegar are good solutions that will penetrate the grout and remove the mold. I put vinegar and allowed it to sit for one hour and then cleaned. I did the same with hydrogen peroxide. However, none of these two household solutions did anything. I'm not sure what else to try? Vinegar and hydrogen peroxide should have removed the black stain. Any other tips?