Hi all. I'm a homeowner in South Florida. I had my pool plastered and new glass tile installed about three weeks ago. The company who did the diamond brite failed to properly service the pool (no chemicals, brushing, etc). Within two weeks I had green algae growing on the grout and calcium deposits on the glass too, but the biggest problem is that the white unsanded tile grout turned a yellowish color where the water spills over from the spa into the pool. At first I thought it might be algae too, but now I think it may be hard water stains.
I'll attach a photo. The reflective nature of the glass and water obscures the color difference somewhat, so hopefully you can still see that the grout to the left is bright white, but the grout in the middle is yellowish. (It looks much worse without sun.)
Here are other factors involved that may be possible clues:
-The plaster company used regular hose water to fill the pool
-The water is spilling over a tumbled travertine spillway. I thought maybe the water running over the natural stone was the culprit, but the grout is yellowing in some other areas not directly under the waterfall (though still nearby the waterfall)
Besides identifying the problem, what I most want to know is how to clean/whiten the grout without damaging the iridescent finish on the NPT Arctic glass tile. I have no idea what level of chemicals the tile can withstand.
Should I use muriatic acid? Or is there another product you recommend?