Gilbert sits in one of the hardest water zones in the East Valley. Municipal reports put the average at 17 to 20 grains per gallon - high enough that plumbers here recommend a whole-home softener as a matter of course. Every time you mop, that hardness deposits calcium and magnesium into the porous sanded grout most Gilbert builders installed between 2001 and 2018. Within 2 to 3 years the joint has absorbed enough mineral scale to lock in every subsequent stain: coffee, wine, cooking oil, dog paws, and monsoon-tracked desert dust.
Then there is the sun. Gilbert averages 300+ sunny days per year, and the same UV that fades your patio furniture destroys the water-based grout sealers big-box stores sell. By month twelve, the sealer is gone and the grout is drinking every spill directly. That is why nearly every Gilbert homeowner who calls us has already tried a Home Depot spray sealer, a grocery-store colorant, and a national tile-cleaning chain - in that order - before finding us.
Layer on monsoon season (July through September dumps fine desert dust onto every horizontal surface in Gilbert) and pet ownership rates well above the Phoenix metro average, and grout in Gilbert has a shorter usable life than grout in almost any other East Valley city. Grout color sealing solves the underlying porosity problem permanently - once epoxy fills the joint, hardness, dust, and stains have nowhere to go.
For the deeper science, read our Gilbert hard water tile & grout damage guide and our DIY vs. professional comparison.