Where it shows up
- Glass shower doors and bathroom mirrors.
- Faucet aerators and showerheads with weakening flow.
- Cloudy film on dishwasher glassware.
- Kettles, coffee makers and ice machines.
- The bottom of the water heater tank, where sediment and scale settle.
Why softened water still spots
WASD's 2024 report describes lime treatment to reduce hardness at its Hialeah plant and enhanced softening at Preston. Softening lowers calcium and magnesium; it does not remove every dissolved mineral. When a film of water evaporates on glass, whatever is dissolved stays behind. Bathrooms without good ventilation keep glass wet longer, which makes spotting worse. Outdoors, untreated well water carries far more minerals and iron, so overspray leaves heavier marks.
Measure before deciding
WASD does not publish a hardness figure for each street. A test at your faucet gives a real number. Low numbers mean a better cleaning routine is enough; higher numbers make a softener worth discussing, especially in a house with a tank water heater or for a business.
Softener versus conditioner
| Ion-exchange softener | Salt-free conditioner | |
|---|---|---|
| Minerals | Removed and exchanged for sodium or potassium | Stay in the water in altered form |
| Spots on glass | Greatly reduced | Can still form as water dries |
| Needs | Main line, drain, salt | Main line, media replacement |
| Renters | Rarely possible | Rarely possible |
More in salt-free vs. ion-exchange.
A routine that works on city water
- Squeegee shower glass after each shower.
- Keep the bathroom ventilated.
- Soak aerators and showerheads in white vinegar every few months.
- Use rinse aid in the dishwasher.
- Descale coffee makers and kettles per the manufacturer.
- Flush the water heater on the manufacturer's schedule.
Scale you cannot see
Spots on glass are cosmetic. Scale inside a tank water heater, a dishwasher or an ice maker is a maintenance issue, because mineral layers slow heating and wear parts. That is the stronger case for softening in a house or a business, and it should rest on a measured hardness number rather than on how the shower door looks. In a rental, flushing the heater is usually the owner's job; it is worth asking when it was last done.
For a restaurant or laundry, even moderate hardness adds up across long operating hours, which is why commercial softening is sized from water bills and a test rather than a rule of thumb.
Book
Call, text or WhatsApp (305) 793-5974. Jorge measures hardness for free and tells you plainly whether equipment is worth it or whether the routine above will do.
Updated 2026-10-17 · Living Waters · Jorge Canela, Water Quality Specialist