Read the clues
What hard water tends to leave behind
Hard water carries dissolved minerals, mainly calcium and magnesium. They can build up as scale on fixtures, inside plumbing and in water heaters, and they can make soap and detergent less effective, which shows up as residue in sinks, tubs and laundry.
These signs suggest hardness but do not measure it. Note where buildup appears, whether it has become more noticeable and which water-using appliances seem affected. A short record like that makes the softener conversation specific to your home.
