Water hardness in Dundrum
23 mg/L soft
Tap water in Dundrum is soft: 23 mg/L (1.4 gpg · 1.3 °dH · 2.3 °fH).
Source: NI Water, customer tap results 2024,2025 (OpenDataNI, OGL v3.0) (2025-11) · data checked 2026-10-20
UK suppliers report mg/L CaCO₃ and often Clark degrees (1 °Clark = 14.25 mg/L).
Water data
| Total hardness | 23 mg/L |
|---|---|
| Utility | Northern Ireland Water |
How Dundrum compares
- Tap water in Dundrum is 87 % softer than the median of the 471 cities we track in the United Kingdom (185 mg/L).
- By hardness it ranks 443 of 471 in the United Kingdom (1 = hardest); 5 % of these cities have softer water.
- In Northern Ireland it is number 94 of 110 cities; the regional median is 100 mg/L.
- Nearest city with clearly harder water: Castlewellan, 6 km away (33 mg/L).
Ranking of the hardest and softest water in the United Kingdom →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Dundrum
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 1 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
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 Dundrum water hard or soft?
It is soft: 23 mg/L as CaCO₃ (1.4 gpg, 1.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Dundrum 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 Dundrum water?
1.4 gpg, equal to 1.3 °dH, 2.3 °fH or 23 mg/L calcium carbonate.
What dishwasher salt setting should I use in Dundrum?
For 23 mg/L (1.3 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Dundrum?
No. With soft water a softener adds nothing.
Source
Source: NI Water, customer tap results 2024,2025 (OpenDataNI, OGL v3.0) (2025-11). Method: own measurement. NI Water, customer tap results 2024,2025 (OpenDataNI, OGL v3.0) · Outdated figure? Tell us