Hey Guys, I have some what looks like iron stains in white carrara. I have already done work here and mixed some iron out in my poultice and it worked. It continues to happen in several condo units.The tile is on the floors and showers. This problem is happening on the floors only. Any suggestions and does anyone know why? Is it the water mixed with the thinset that makes it react this way? This install is about 1 year old.