Hard water in the South Bay, and what it does

What hard water actually is

Water picks up dissolved calcium and magnesium on its way to you. Neither is harmful to drink. Both come out of solution when water evaporates or is heated, and what they leave behind is scale: the hard white deposit on the kettle element, the aerator and the showerhead.

Hardness here is not uniform. It depends on whether your street is fed from imported surface water, from local groundwater, or from a blend, and it can differ noticeably between neighbourhoods in the same city. Your water utility publishes an annual water quality report with the figures for your area, and that is the number to go on rather than a general claim about the region.

Where you see it first

• The aerator. The little screen in the end of the faucet spout. It clogs unevenly, so the stream starts splitting or spraying sideways. Unscrew it, soak it in white vinegar for an hour, brush it out, screw it back. This is five minutes and it fixes a complaint most people live with for years.
• The showerhead. Same problem, same fix. If some of the holes are blocked solid, a rubber-nozzle head can be rubbed clean with a thumb.
• Glass shower doors. Scale etches glass over time, and past a certain point it is in the surface rather than on it. Nothing you spray on will bring that back. Squeegeeing after a shower is dull advice that genuinely works.
• Toilet fill valves and flappers. Scale stops them seating cleanly, which is one reason an older toilet starts running intermittently.
• Dark finishes. Matte black and oil-rubbed bronze show a white film within days here. Worth knowing before you buy, not after.

What helps, in order of value

Vinegar and a brush, twice a year. Costs nothing, takes twenty minutes for the whole house, and prevents most of what people eventually call somebody about.

A squeegee in the shower. Protects the glass, which is the only part of this that cannot be undone later.

Replacing an aerator rather than cleaning it. They cost a couple of dollars. If yours is twenty years old and corroded into the spout, a new one restores the stream better than any amount of soaking.

A whole-house softener. Genuinely effective, and a real plumbing installation with real cost, a drain requirement and ongoing salt. It needs a licensed plumber, not me. Worth looking into if you are also fighting scale in a water heater and a dishwasher. Overkill if your only complaint is the kitchen faucet.

Magnetic and electronic "descalers". I would not spend money on these.

What hard water does to caulk and grout

Scale builds up along the joint where the tub meets the tile and holds moisture against it, which is part of why caulk in a hard-water area discolours and lets go sooner than the tube promises. Cleaning the joint and resealing it every few years is normal maintenance here, not a sign anything was done badly.

The thing to watch for is different: if the joint feels soft when you press it, or the board behind the tile gives slightly, water has been getting past the caulk for a while. That is worth looking at properly rather than sealing over.

What this costs if you would rather not

Most of this page is deliberately unpaid work — an aerator and a showerhead are yours and a bottle of vinegar's. Where it stops being a cleaning job is when a fixture is scaled beyond saving, or when caulk has been failing long enough that something behind it got wet. Both of those are worth a photo.