Water hardness in Tarragona
31.3 °fH very hard
Tap water in Tarragona is very hard: 31.3 °fH (313 mg/L · 18.3 gpg · 17.5 °dH).
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 43148 (2026-08) · data checked 2026-10-19
Range across supply zones: 263–340 mg/L.
Supply in the Camp de Tarragona area relies largely on the Ebro river and on local limestone aquifers. Official analyses put the water at 313 mg/L CaCO₃, very hard, with values between 263 and 340 mg/L. Limestone and sedimentary rock dissolve plenty of calcium and magnesium, hence the high hardness. Scale on taps and shower screens is common, and water-heater elements foul sooner.
Fuentes españolas usan °fH (grados hidrotimétricos franceses) o mg/L CaCO₃.
Water data
| Total hardness | 31.3 °fH |
|---|
How Tarragona compares
- Tap water in Tarragona is 56 % harder than the median of the 4988 cities we track in Spain (20.1 °fH).
- By hardness it ranks 1304 of 4988 in Spain (1 = hardest); 74 % of these cities have softer water.
- In Tarragona it is number 121 of 181 cities; the regional median is 35.4 °fH.
- Nearest city with clearly softer water: Alió, 20 km away (22.8 °fH).
- Nearest city with clearly harder water: Canonja, La, 7 km away (43.3 °fH).
Ranking of the hardest and softest water in Spain →
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 Tarragona
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 18 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| 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 Tarragona water hard or soft?
It is very hard: 313 mg/L as CaCO₃ (18.3 gpg, 17.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Tarragona 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 Tarragona water?
18.3 gpg, equal to 17.5 °dH, 31.3 °fH or 313 mg/L calcium carbonate.
What dishwasher salt setting should I use in Tarragona?
For 313 mg/L (17.5 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Tarragona?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 43148 (2026-08). Method: own measurement. SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 43148 · Outdated figure? Tell us