Water hardness in Carcavelos
90 mg/L moderately hard
Tap water in Carcavelos is moderately hard: 90 mg/L (5.2 gpg · 5 °dH · 8.9 °fH).
Source: Águas de Cascais - Controlo de qualidade da água de 2024 (Ca, Mg, dureza, K por zona) (2024) · data checked 2026-11-07
Range across supply zones: 60–119 mg/L.
Águas de Cascais lists Carcavelos in Zona 6 of its 2024 zone table: 60 to 119 mg/L CaCO₃. The 89.5 mg/L shown is the midpoint of that range, not a measurement taken in Carcavelos. The figures were read from an image table, and neighbouring zones in Cascais can be much harder. Moderate hardness means occasional descaling of kettles and showerheads.
Portuguese operators report "dureza total" in mg/L CaCO₃ to ERSAR.
Water data
| Total hardness | 90 mg/L |
|---|---|
| Utility | Águas de Cascais |
How Carcavelos compares
- Tap water in Carcavelos is 7 % harder than the median of the 77 cities we track in Portugal (83 mg/L).
- By hardness it ranks 32 of 77 in Portugal (1 = hardest); 57 % of these cities have softer water.
- In 14 it is number 1 of 19 cities; the regional median is 75 mg/L.
- Nearest city with clearly softer water: Oeiras, 1 km away (42 mg/L).
- Nearest city with clearly harder water: Alcabideche, 9 km away (289 mg/L).
Ranking of the hardest and softest water in Portugal →
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 Carcavelos
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| 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 Carcavelos water hard or soft?
It is moderately hard: 90 mg/L as CaCO₃ (5.2 gpg, 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 Carcavelos safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Portuguese operators report "dureza total" in mg/L CaCO₃ to ERSAR.
How many grains per gallon is Carcavelos water?
5.2 gpg, equal to 5 °dH, 8.9 °fH or 90 mg/L calcium carbonate.
What dishwasher salt setting should I use in Carcavelos?
For 90 mg/L (5 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Carcavelos?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Águas de Cascais - Controlo de qualidade da água de 2024 (Ca, Mg, dureza, K por zona) (2024). Method: computed from supplier's calcium and magnesium. Águas de Cascais - Controlo de qualidade da água de 2024 (Ca, Mg, dureza, K por zona) · Outdated figure? Tell us