Hard water marks are the white or gray spots and crust left when water dries and leaves its minerals behind. Most come off glass, glazed tile and chrome with a 50/50 mix of white vinegar and water, left for a few minutes and rinsed off. Keep vinegar off marble, travertine, limestone and terrazzo, and never mix it with bleach.
How hard is the water here?
The annual water quality reports we checked from the 3 main utilities do not list a hardness figure. They do show where the water comes from and how it is treated:
| Utility | Where the water comes from | Hardness in the report |
|---|---|---|
| City of West Palm Beach Utilities, which also serves Palm Beach and South Palm Beach | Surface water: rain collected in Grassy Waters Preserve and stored in Lake Mangonia and Clear Lake | Not listed. The 2025 report gives total dissolved solids of 243 ppm |
| City of Lake Worth Beach Utilities | Groundwater from shallow wells in the Surficial and Biscayne Aquifers and deep Floridan Aquifer wells | Not listed. Water goes through a lime softening plant and a reverse osmosis plant and is blended |
| Palm Beach County Water Utilities | Groundwater from the Biscayne and Floridan Aquifers | Not listed. Its plants use lime softening and ion exchange, nanofiltration and reverse osmosis |
From each utility's annual drinking water quality report, checked on November 3, 2026. Your water bill shows which utility supplies you.
Softening reduces hardness, but treated water still carries dissolved minerals that are left behind where it dries. For a hardness figure for your supply, ask your utility. Palm Beach County Water Utilities is on (561) 740 4600. The US Geological Survey classes water up to 60 mg/L, measured as calcium carbonate, as soft, 61 to 120 as moderately hard, 121 to 180 as hard and over 180 as very hard. Hardness also causes soap scum and spots on glasses.
How to remove the marks
| Where | What to do |
|---|---|
| Shower glass | Spray a 50/50 mix of white vinegar and water, leave it 5 to 10 minutes, scrub with a non scratch sponge, rinse and squeegee dry. A paste of baking soda and water helps on heavy build up |
| Faucets and fixtures | Moen says a 50/50 mix of vinegar and water can be used for a limited time, then rinsed off and dried with a soft cloth. Avoid harsh lime scale removers and scouring pads on plated and coated finishes, and check your fixture maker's care guide |
| Shower heads | Soak the face in a bag of diluted vinegar tied over it, then run hot water through and rub the nozzles with an old toothbrush. Check the maker's guidance for the finish first |
| Toilets | Pour white vinegar into the bowl, leave it for a few hours, then scrub with a toilet brush. For a stubborn ring, use a wet pumice stone made for toilets, gently |
| Glazed ceramic tile | Diluted vinegar, rinsed off well. Our grout guide covers the grout lines |
Vinegar cautions
- Not on natural stone or terrazzo. Acids such as vinegar dissolve parts of calcareous stone such as marble and limestone and leave dull etch marks. Many vanity tops, shower walls and older floors here are stone or terrazzo. See cleaning terrazzo floors
- Never with bleach. The CDC says never to mix bleach with ammonia or any other cleaner. Rinse one product off completely before you use another
- Rinse it off. Do not leave vinegar sitting on metal finishes, rubber seals or grout
- Test first. Try any cleaner on a hidden spot
Keep the marks from coming back
- Squeegee shower glass and wipe faucets dry after use
- Run the bathroom fan so surfaces dry faster
- Clean marks every week while they are thin, before they build into crust
- A water softener is an option for homeowners. Tenants need the landlord's agreement before installing one
A deep clean includes removing hard water build up from showers, glass and fixtures. Send a request and a local cleaner will call you to quote.
Sources
- City of West Palm Beach Public Utilities: 2025 water quality report
- City of Lake Worth Beach: 2022 annual drinking water quality report
- Town of Lake Clarke Shores: 2025 drinking water quality report, water supplied by Lake Worth Beach
- Palm Beach County Water Utilities Department: 2025 water quality report
- US Geological Survey: Hardness of water
- Moen: Faucet finish care and cleaning
- US General Services Administration: Removing etch marks in marble
- CDC: Guidelines for cleaning safely after a disaster, including bleach safety