What are the white calcium deposits on my faucets and how do I remove them?

The City of Phoenix reports total hardness of 172 to 302 mg/L, or 10 to 17.6 grains per gallon, in its 2025 report, and says hard water "can cause some types of scaling in pipes and water heaters, and on plumbing fixtures such as faucets and showerheads." The deposits show up where water dries slowly: the base of the spout, around the handle, on the aerator screen, and along the sink deck where drops sit.

EPCOR, which serves part of the West Valley, makes the safety point plainly: "Hardness and/or the deposits left by hard water don't pose a health concern." The cost of scale is mostly looks, plus parts that get harder to loosen once buildup sets around handles and aerators.

Most white crust on a faucet that sits where water drips and dries is mineral scale. If your brand allows vinegar (see the next sections), a cloth soaked in white vinegar and held on a small patch is a fair test, because EPCOR notes that cleaning with white vinegar can help dissolve and remove these deposits. Crust that softens and wipes away is scale.

White or greenish crust that returns quickly at a joint, under the handle or where the supply line meets the faucet, with dampness underneath, is worth a second look, because a slow drip can leave the same residue. Dry the area, put a paper towel under the joint, and see whether it is damp an hour later. If it is, you have a leak to fix, not a stain to scrub. Our guide to fixing a dripping faucet covers that case.

Start with the gentlest option and work up only as far as you need.

1. 1Wipe with mild dish soap and water, then dry. Moen, for one, lists a damp cloth and mild liquid dish soap, rinsed and dried with a soft cloth, as the general cleaning instruction for its finishes.
2. 2Move to vinegar for the stubborn spots. Kohler's support page says a 50/50 solution of white vinegar and warm water "may also be used to remove hard water build up from a faucet," applied with a clean cloth or soft sponge. Moen gives the same mix for dried water spots and adds "for a limited amount of time," followed by rinsing with water and drying with a soft cloth.
3. 3Loosen heavy buildup around a handle. Kohler describes soaking a towel in the vinegar solution, wrapping it around the bonnet or skirt of the handle for approximately five to ten minutes, then using a rubber glove or rubber jar opener for grip to turn the bonnet counterclockwise. Kohler also warns that removing handles or aerators with considerable buildup can be difficult, so do not force a part that will not budge.
4. 4Soak the aerator if the spout tip is crusted. Pfister's support page says to unscrew the aerator counterclockwise, submerge it in a 50/50 mix of warm water and white vinegar for approximately 60 minutes, then use a soft cloth on the aerator housing and spout tip.
5. 5Rinse and dry every time. Dry metal does not spot, and a minute with a towel after use prevents most of the return crust.

Makers do not all agree that acid is fine, which is where people damage finishes. Pfister's care page says to avoid "polish, detergents, abrasive cleaners, organic solvents or any product that has acid in it," and states this "will nullify your limited lifetime warranty and damage the finish." Yet Pfister's own support article for hard water spots describes a 50/50 warm water and white vinegar solution on a soft cloth, followed by mild soap and water, and says that "Use of any acids or solvents on your faucet would void any warranty you may have." Read together, that points to a diluted vinegar wipe for spots and nothing stronger. American Standard is flatter: it says to never use "soaps, acids, polish, abrasives, harsh cleaners, or cloth with a coarse surface," and recommends rinsing with clear water and drying with a soft cotton cloth.

If your brand is American Standard, or you cannot find your maker's page, start with a soft damp cloth and clear water, and call the manufacturer before you reach for vinegar.

Moen's guidance is more nuanced. It allows the vinegar mix for spots on its finish families, but says to avoid harsh cleansers "(e.g., lime scale removers)" and abrasive pads, adding that "Failure to comply with these cleaning instructions may void Moen's warranty." For its powder-coat finishes, including Matte Black, it tells you to avoid abrasive sponges and steel wool. If you have a matte or textured finish, our page on cleaning matte black and brushed nickel faucets goes into the brand rules in detail.

Skip commercial lime-scale removers unless the manufacturer lists them. Moen names lime scale removers among the cleaners to avoid, and American Standard rules out acids altogether.

Wiping the faucet dry is the cheapest prevention there is. Moen also suggests a periodic coat of non-abrasive wax, such as car wax or furniture wax, on matte or textured finishes, noting that wax will cause a slight color change but will not harm the finish, and recommends testing a less visible spot first.

If the scale is everywhere, on the showerheads, glass and dishwasher too, the faucet is only the visible symptom. See how hard water damages plumbing and whether a softener works in Arizona, and note that how hard your Valley water is varies by city. A water softening system addresses scale at the source, and an HQ plumber can take a look at your fixtures and supply lines during the same visit.