Water hardness in El Paso de Robles (Paso Robles)
13.1 gpg very hard
Tap water in El Paso de Robles (Paso Robles) is very hard: 13.1 gpg (225 mg/L · 12.6 °dH · 22.5 °fH).
Source: City of Paso Robles Water Quality Report 2023 (2023) · data checked 2026-11-02
Range across supply zones: 110–490 mg/L.
The City of Paso Robles Water Division published a 2023 report with a median hardness of 225 mg/L as CaCO₃. Individual readings run from 110 to 490 mg/L, a wide spread that suggests several sources with different mineral content; the report summary does not say which. Overall the water is very hard, so scale on heaters and fixtures is common and a softener is worth considering.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 13.1 gpg |
|---|---|
| Utility | City of Paso Robles Water Division (PWS CA4010007) |
How El Paso de Robles (Paso Robles) compares
- Tap water in El Paso de Robles (Paso Robles) is 45 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 444 of 1372 in the United States (1 = hardest); 67 % of these cities have softer water.
- In California it is number 95 of 336 cities; the regional median is 9.5 gpg.
Ranking of the hardest and softest water in the United States →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in El Paso de Robles (Paso Robles)
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 13 °dH |
| AEG / Electrolux | 3 |
| Beko | 3rd |
| Hoover | S2 |
| LG | H2 |
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 El Paso de Robles (Paso Robles) water hard or soft?
It is very hard: 225 mg/L as CaCO₃ (13.1 gpg, 12.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in El Paso de Robles (Paso Robles) 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 El Paso de Robles (Paso Robles) water?
13.1 gpg, equal to 12.6 °dH, 22.5 °fH or 225 mg/L calcium carbonate.
What dishwasher salt setting should I use in El Paso de Robles (Paso Robles)?
For 225 mg/L (12.6 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in El Paso de Robles (Paso Robles)?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: City of Paso Robles Water Quality Report 2023 (2023). Method: figure published by the water supplier. City of Paso Robles Water Quality Report 2023 · Outdated figure? Tell us