The hose comes off the reel and runs a sprinkler for an hour. Afterward, there is a dark patch under the spigot that was not there before, and it stays dark long after the sun should have dried it.

The softener went in six weeks ago. The brine tank has salt in it; the shampoo lathers with about half as much as you used to squeeze out; and the shower door feels different under your hand when you wipe it.

Under the lid of one toilet sits a tank of standing water held back by a rubber flapper.

Every drain in your house works on fall. Water and waste leave your fixtures, run downhill through pipes sloped toward the main sewer line, and never need a push.

You turn the lever, and you can feel it through your hand. The travel has a fine grinding in it, as though something small is riding between two surfaces.

You start a load of laundry, and a few minutes later the toilet gurgles or a ring of bubbles rises in the bowl.

Anthem's tap water tests at 18 grains per gallon. Here's what that hardness does to water heaters, fixtures, and pipes — and how to slow it down.