Thanks steve for the advice. I have a cement slab foundation.The stains on some of the tiles is just one spot on one tile then it skips several tiles and then it reappears again. However right next to the wall board it is a on every single tile all the way down. I havent tried bleach yet but I have tried several diffrent acids that are suppost to clean tile With little or no results. I am thinking I might just need new tile. I will try the bleach. Thank you.