Water hardness in Pasadena
10 gpg hard
Tap water in Pasadena is hard: 10 gpg (171 mg/L · 9.6 °dH · 17.1 °fH).
Source: Pasadena Water and Power 2026 Water Quality Report (2025 data) (2026) · data checked 2026-10-19
Range across supply zones: 89–256 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| Cal-Am Water Company - East Pasadena | 7 | 120 | hard |
| citywide | 13 | 222 | very hard |
Pasadena Water and Power's 2026 report, covering 2025 data, gives a hardness of 222 mg/L (13.0 gpg), with a range of 202 to 256 mg/L. The water is very hard, and the range is fairly narrow. Scale builds quickly on heaters and fixtures, 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 | 10 gpg |
|---|---|
| Utility | Pasadena Water and Power (PWP) |
How Pasadena compares
- Tap water in Pasadena is 10 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 624 of 1372 in the United States (1 = hardest); 55 % of these cities have softer water.
- In California it is number 155 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: East Pasadena, 7 km away (5.2 gpg).
- Nearest city with clearly harder water: Arcadia, 10 km away (14.2 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Pasadena
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S1 |
| 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 Pasadena water hard or soft?
It is hard: 171 mg/L as CaCO₃ (10 gpg, 9.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Pasadena 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 Pasadena water?
10 gpg, equal to 9.6 °dH, 17.1 °fH or 171 mg/L calcium carbonate.
What dishwasher salt setting should I use in Pasadena?
For 171 mg/L (9.6 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Pasadena?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Pasadena Water and Power 2026 Water Quality Report (2025 data) (2026). Method: own measurement. Pasadena Water and Power 2026 Water Quality Report (2025 data) · Outdated figure? Tell us