Water hardness in Oiartzun
1.5 °fH soft
Tap water in Oiartzun is soft: 1.5 °fH (15 mg/L · 0.9 gpg · 0.8 °dH).
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 20063 (2024-10) · data checked 2026-10-19
Range across supply zones: 13–17 mg/L.
SINAC, the Ministry of Health's drinking-water register, reports 15 mg/L CaCO₃ for Oiartzun, soft, with values between 13 and 17 mg/L. The latest reading dates from October 2024. Towns around San Sebastián are harder, from 38.5 to 75.5 mg/L. Scale is hardly an issue here.
Fuentes españolas usan °fH (grados hidrotimétricos franceses) o mg/L CaCO₃.
Water data
| Total hardness | 1.5 °fH |
|---|
How Oiartzun compares
- Tap water in Oiartzun is 93 % softer than the median of the 4988 cities we track in Spain (20.1 °fH).
- By hardness it ranks 4770 of 4988 in Spain (1 = hardest); 4 % of these cities have softer water.
- In Guipúzcoa it is number 85 of 86 cities; the regional median is 15.3 °fH.
- Nearest city with clearly softer water: Hornos de Moncalvillo, 112 km away (0.8 °fH).
- Nearest city with clearly harder water: Astigarraga, 8 km away (4.9 °fH).
Ranking of the hardest and softest water in Spain →
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 Oiartzun
| 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 Oiartzun water hard or soft?
It is soft: 15 mg/L as CaCO₃ (0.9 gpg, 0.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Oiartzun 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 Oiartzun water?
0.9 gpg, equal to 0.8 °dH, 1.5 °fH or 15 mg/L calcium carbonate.
What dishwasher salt setting should I use in Oiartzun?
For 15 mg/L (0.8 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Oiartzun?
No. With soft water a softener adds nothing.
Source
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 20063 (2024-10). Method: own measurement. SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 20063 · Outdated figure? Tell us