Water hardness in Selby
287 mg/L very hard
Tap water in Selby is very hard: 287 mg/L (16.8 gpg · 16.1 °dH · 28.7 °fH).
Source: Yorkshire Water — domestic drinking water quality (Stream open data, CC BY) (2026-10) · data checked 2026-10-19
Range across supply zones: 256–302 mg/L.
Yorkshire Water supplies Selby from a network that blends reservoir, river and borehole sources, and the company links harder water in the east of the region to its borehole and groundwater supplies. Reported hardness is 287.2 mg/L CaCO₃, ranging from 256.0 to 302.2 mg/L between supply zones. The harder supply reflects borehole and groundwater sources, which pick up calcium and magnesium from the rock; expect visible limescale on taps, kettles and in boilers; a softener or scale inhibitor is worth considering, especially for hot-water systems.
UK suppliers report mg/L CaCO₃ and often Clark degrees (1 °Clark = 14.25 mg/L).
Water data
| Total hardness | 287 mg/L |
|---|---|
| Utility | Yorkshire Water |
How Selby compares
- Tap water in Selby is 56 % harder than the median of the 471 cities we track in the United Kingdom (185 mg/L).
- By hardness it ranks 111 of 471 in the United Kingdom (1 = hardest); 76 % of these cities have softer water.
- In Selby it is number 2 of 4 cities; the regional median is 286 mg/L.
- Nearest city with clearly softer water: Tadcaster, 17 km away (152 mg/L).
- Nearest city with clearly harder water: Cottingham, 43 km away (371 mg/L).
Ranking of the hardest and softest water in the United Kingdom →
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 Selby
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 16 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S2 |
| LG | H3 |
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 Selby water hard or soft?
It is very hard: 287 mg/L as CaCO₃ (16.8 gpg, 16.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Selby 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 Selby water?
16.8 gpg, equal to 16.1 °dH, 28.7 °fH or 287 mg/L calcium carbonate.
What dishwasher salt setting should I use in Selby?
For 287 mg/L (16.1 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Selby?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Yorkshire Water — domestic drinking water quality (Stream open data, CC BY) (2026-10). Method: own measurement. Yorkshire Water — domestic drinking water quality (Stream open data, CC BY) · Outdated figure? Tell us