Water hardness in Martos
32.7 °fH very hard
Tap water in Martos is very hard: 32.7 °fH (327 mg/L · 19.1 gpg · 18.3 °dH).
Source: SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 23060 (2026-09) · data checked 2026-10-19
Range across supply zones: 181–379 mg/L.
For Martos, SINAC (the Ministry of Health's water-supply system) records 327 mg/L CaCO₃, with readings from 181 to 379 mg/L as of September 2026. In this part of Jaén carbonate aquifers in the Subbetic ranges and intakes from the Guadalquivir and its tributaries dominate, which is why the water tends to be hard. With water this hard, scale shortens the life of heating elements and hot-water pipes and often justifies treatment at home.
Fuentes españolas usan °fH (grados hidrotimétricos franceses) o mg/L CaCO₃.
Water data
| Total hardness | 32.7 °fH |
|---|
How Martos compares
- Tap water in Martos is 63 % harder than the median of the 4988 cities we track in Spain (20.1 °fH).
- By hardness it ranks 1176 of 4988 in Spain (1 = hardest); 76 % of these cities have softer water.
- In Jaén it is number 23 of 96 cities; the regional median is 24.6 °fH.
- Nearest city with clearly softer water: Villares, Los, 15 km away (18.6 °fH).
- Nearest city with clearly harder water: Fuensanta de Martos, 10 km away (53 °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 Martos
| 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 Martos water hard or soft?
It is very hard: 327 mg/L as CaCO₃ (19.1 gpg, 18.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Martos 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 Martos water?
19.1 gpg, equal to 18.3 °dH, 32.7 °fH or 327 mg/L calcium carbonate.
What dishwasher salt setting should I use in Martos?
For 327 mg/L (18.3 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Martos?
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 23060 (2026-09). Method: own measurement. SINAC, Ministerio de Sanidad — Información de un abastecimiento, municipio 23060 · Outdated figure? Tell us