1. A Chalky White Band at the Waterline
The most obvious sign is a rough, white or gray band running along the tile at the water's surface — calcium that has bonded to the tile as water evaporated and minerals concentrated in North Texas's hard water.
2. Rough Texture You Can Feel
Run a hand along the tile line — if it feels gritty rather than smooth, scale has already built up enough to change the surface texture. This stage is still very treatable with professional descaling.
3, 4, and 5: Cloudy Tile, Grout Discoloration, and Faster Re-Buildup
Glass and ceramic tile losing their shine, grout lines turning white or yellow, and scale returning within just a few months of your last cleaning are all signs that professional attention is needed rather than another round of DIY scrubbing.