My celaka contraktor washed my house with acid, but did not sweep it dry. I duno how long after that onli i visited my house & see pools of water on the floor. Faster2 rinse with pails of water. Too late.. the area submerged in water -> grout lines offcolour & the tile edges look like smudged, & dulled & these are niro tiles !

This post has been edited by mrPOTATO: Sep 10 2011, 08:35 PM

I oso got suggestion.. if really grout yellowed, ace got sell small tubes like correction pen, jus run it along the lines.