Water hardness in Redondo Beach
29.3 gpg very hard
Tap water in Redondo Beach is very hard: 29.3 gpg (502 mg/L · 28.1 °dH · 50.2 °fH).
Source: Cal Water Hermosa-Redondo System 2025 Water Quality Report (CCR) (2025) · data checked 2026-10-23
Range across supply zones: 486–517 mg/L.
Cal Water serves Redondo Beach with local groundwater, treated at wellheads to remove iron and manganese, and imported Colorado River and State Water Project water from Metropolitan. Basin groundwater and imported supply are both mineral-rich, giving extremely hard water at 502 mg/L CaCO₃ (486–517 mg/L). A softener is practically essential.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 29.3 gpg |
|---|---|
| Calcium (mg/L) | 141 |
| Magnesium (mg/L) | 37 |
| Utility | California Water Service (Cal Water), Hermosa-Redondo district |
How Redondo Beach compares
- Tap water in Redondo Beach is 224 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 11 of 1372 in the United States (1 = hardest); 99 % of these cities have softer water.
- In California it is number 5 of 336 cities; the regional median is 9.5 gpg.
- Nearest city with clearly softer water: Manhattan Beach, 6 km away (22.9 gpg).
- Nearest city with clearly harder water: Piru, 73 km away (37.8 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 Redondo Beach
| Brand | Setting for this water |
|---|---|
| Bosch | H06 |
| Miele | 28 °dH |
| AEG / Electrolux | 6 |
| Beko | 6th |
| Hoover | S4 |
| LG | H4 |
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 Redondo Beach water hard or soft?
It is very hard: 502 mg/L as CaCO₃ (29.3 gpg, 28.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Redondo Beach 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 Redondo Beach water?
29.3 gpg, equal to 28.1 °dH, 50.2 °fH or 502 mg/L calcium carbonate.
What dishwasher salt setting should I use in Redondo Beach?
For 502 mg/L (28.1 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Redondo Beach?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Cal Water Hermosa-Redondo System 2025 Water Quality Report (CCR) (2025). Method: figure published by the water supplier. Cal Water Hermosa-Redondo System 2025 Water Quality Report (CCR) · Outdated figure? Tell us