Water hardness in Sestao
8.1 °fH moderately hard
Tap water in Sestao is moderately hard: 8.1 °fH (81 mg/L · 4.7 gpg · 4.5 °dH).
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 48084 (2024-02) · data checked 2026-10-19
Range across supply zones: 73–89 mg/L.
Supply depends on the Consorcio de Aguas Bilbao Bizkaia reservoirs, in high-rainfall catchments. Official analyses put the water at 81 mg/L CaCO₃, moderately hard, with values between 73 and 89 mg/L. A mix of sources with different mineral content gives an intermediate value. Some scale builds up in kettles and taps over time; an occasional descale is usually enough.
Fuentes españolas usan °fH (grados hidrotimétricos franceses) o mg/L CaCO₃.
Water data
| Total hardness | 8.1 °fH |
|---|
How Sestao compares
- Tap water in Sestao is 60 % softer than the median of the 4988 cities we track in Spain (20.1 °fH).
- By hardness it ranks 3821 of 4988 in Spain (1 = hardest); 23 % of these cities have softer water.
- In Vizcaya it is number 80 of 93 cities; the regional median is 10.1 °fH.
- Nearest city with clearly softer water: Bermeo, 25 km away (4.5 °fH).
- Nearest city with clearly harder water: Etxebarri, 11 km away (10.3 °fH).
Ranking of the hardest and softest water in Spain →
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 Sestao
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °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 Sestao water hard or soft?
It is moderately hard: 81 mg/L as CaCO₃ (4.7 gpg, 4.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Sestao safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Fuentes españolas usan °fH (grados hidrotimétricos franceses) o mg/L CaCO₃.
How many grains per gallon is Sestao water?
4.7 gpg, equal to 4.5 °dH, 8.1 °fH or 81 mg/L calcium carbonate.
What dishwasher salt setting should I use in Sestao?
For 81 mg/L (4.5 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Sestao?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 48084 (2024-02). Method: own measurement. SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 48084 · Outdated figure? Tell us