HELP - Shower floor grout turning blue/green
We had master bathroom completed 4 months ago. While cleaning the white marble tile shower floor I noticed we are getting a slight blue/green staining to some of the grout lines. It isn't horrible yet, but obviously I want to get rid of the stains and stop any future staining.
We used Laticrete Epoxy grout in white. Marble (not grout) was sealed prior to grouting. I though epoxy grout was bullet proof but I can't get the stains out with just scrubbing. Any suggestions on what we can use to get the stains that is safe to use with marble?
Also trying to figure out what is causing the stains as we don't have this issue anywhere else in our house. The products we use in the shower are not colored or have any dyes.
So far I have read two things....both relating to the water. We have public water and when we first moved in we had the water tested and it was slightly hard. We don't have a softener. Don't recall the ph level.
1) Copper. Stain can happen when there is copper content in water and it is able to stand & evaporate. Typically comes from copper pipes corroding due to acidic (low pH) water.
2) Chlorine. Our public water uses chloramine (chlorine and ammonia) and from what I read that can also turn things blue if let to stand and evaporate.
I am going to get a water test kit however I don't know the levels of what is good or bad with these items to know which if either would cause blue/green staining.
Anyone else encounter this issue and resolve it?