Water hardness in Spa
7.5 °fH moderately hard
Tap water in Spa is moderately hard: 7.5 °fH (75 mg/L · 4.4 gpg · 4.2 °dH).
Source: SPW, qualité de l'eau potable par zone de distribution, année civile 2025 (2025) · data checked 2026-10-19
Spa, in the province of Liège, is supplied by SWDE. The SPW 2025 report for its distribution zone gives 74.5 mg/L CaCO₃, a moderate level and much softer than most towns in this batch. Scale is limited, so a softener is rarely needed.
Belgian suppliers report hardness in °f (French degrees); 1 °f = 10 mg/L CaCO₃.
Water data
| Total hardness | 7.5 °fH |
|---|---|
| Utility | SWDE |
How Spa compares
- Tap water in Spa is 76 % softer than the median of the 1091 cities we track in Belgium (31.6 °fH).
- By hardness it ranks 1028 of 1091 in Belgium (1 = hardest); 4 % of these cities have softer water.
- In Liège it is number 200 of 237 cities; the regional median is 27.3 °fH.
- Nearest city with clearly softer water: La Reid, 5 km away (4.7 °fH).
- Nearest city with clearly harder water: Theux, 7 km away (16.6 °fH).
Ranking of the hardest and softest water in Belgium →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Spa
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 4 °dH |
| AEG / Electrolux | 2 |
| Beko | 1st |
| Hoover | S1 |
| LG | H1 |
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 Spa water hard or soft?
It is moderately hard: 75 mg/L as CaCO₃ (4.4 gpg, 4.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Spa safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Belgian suppliers report hardness in °f (French degrees); 1 °f = 10 mg/L CaCO₃.
How many grains per gallon is Spa water?
4.4 gpg, equal to 4.2 °dH, 7.5 °fH or 75 mg/L calcium carbonate.
What dishwasher salt setting should I use in Spa?
For 75 mg/L (4.2 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Spa?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: SPW, qualité de l'eau potable par zone de distribution, année civile 2025 (2025). Method: figure published by the water supplier. SPW, qualité de l'eau potable par zone de distribution, année civile 2025 · Outdated figure? Tell us