Water hardness in Slinfold
180 mg/L hard
Tap water in Slinfold is hard: 180 mg/L (10.5 gpg · 10.1 °dH · 18 °fH).
Source: Southern Water — domestic drinking water quality (Stream open data, CC BY) (2026-02) · data checked 2026-10-20
Range across supply zones: 134–185 mg/L.
UK suppliers report mg/L CaCO₃ and often Clark degrees (1 °Clark = 14.25 mg/L).
Water data
| Total hardness | 180 mg/L |
|---|---|
| Utility | Southern Water |
How Slinfold compares
- Tap water in Slinfold is close to the median of the 471 cities we track in the United Kingdom (185 mg/L).
- By hardness it ranks 238 of 471 in the United Kingdom (1 = hardest); 50 % of these cities have softer water.
- In Horsham it is number 3 of 13 cities; the regional median is 169 mg/L.
- Nearest city with clearly softer water: Hastings, 73 km away (81 mg/L).
- Nearest city with clearly harder water: Ashurst, 17 km away (282 mg/L).
Ranking of the hardest and softest water in the United Kingdom →
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 Slinfold
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| 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 Slinfold water hard or soft?
It is hard: 180 mg/L as CaCO₃ (10.5 gpg, 10.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Slinfold safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. UK suppliers report mg/L CaCO₃ and often Clark degrees (1 °Clark = 14.25 mg/L).
How many grains per gallon is Slinfold water?
10.5 gpg, equal to 10.1 °dH, 18 °fH or 180 mg/L calcium carbonate.
What dishwasher salt setting should I use in Slinfold?
For 180 mg/L (10.1 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Slinfold?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Southern Water — domestic drinking water quality (Stream open data, CC BY) (2026-02). Method: own measurement. Southern Water — domestic drinking water quality (Stream open data, CC BY) · Outdated figure? Tell us