Water hardness in Lake Zurich
7 gpg moderately hard
Tap water in Lake Zurich is moderately hard: 7 gpg (120 mg/L · 6.7 °dH · 12 °fH).
Source: Village of Lake Zurich - Water Quality (2025) · data checked 2026-10-29
Range across supply zones: 103–137 mg/L.
Lake Zurich's Public Works publishes values that give a computed hardness of 119.8 mg/L, ranging from 102.7 to 137 mg/L. That is moderate, touching hard at the top of the range. Check the village's water quality page for the latest sampling.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 7 gpg |
|---|---|
| Utility | Village of Lake Zurich Public Works |
How Lake Zurich compares
- Tap water in Lake Zurich is 23 % softer than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 903 of 1372 in the United States (1 = hardest); 34 % of these cities have softer water.
- In Illinois it is number 12 of 14 cities; the regional median is 8 gpg.
Ranking of the hardest and softest water in the United States →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Lake Zurich
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 7 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Lake Zurich water hard or soft?
It is moderately hard: 120 mg/L as CaCO₃ (7 gpg, 6.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Lake Zurich safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Lake Zurich water?
7 gpg, equal to 6.7 °dH, 12 °fH or 120 mg/L calcium carbonate.
What dishwasher salt setting should I use in Lake Zurich?
For 120 mg/L (6.7 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Lake Zurich?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Village of Lake Zurich - Water Quality (2025). Method: computed from supplier's calcium and magnesium. Village of Lake Zurich - Water Quality · Outdated figure? Tell us