My customer’s granite tile floor has developed several white streaks. They’ve tried several things but they don’t seem to go away. What can I suggest they use to clean them off?

These white streaks may be hard-water deposits, which can prove very difficult to remove. Suggest that they try a sulfamic acid-based tile-and-grout cleaner -- Stonecare PRO Signature’s HEAVY DUTY Tile and Grout Cleaner.

CAUTION Make sure to let them know to NOT use sulfamic acid or any acids on marble. Acid will etch the marble and repolishing will be necessary.