Water hardness in Rio de Mouro
50 mg/L soft
Tap water in Rio de Mouro is soft: 50 mg/L (2.9 gpg · 2.8 °dH · 5 °fH).
Source: SMAS Sintra - Dureza por freguesia (table dated 06/06/2024) (2024-06) · data checked 2026-10-21
Range across supply zones: 40–60 mg/L.
SMAS Sintra's parish table, dated 6 June 2024, lists Rio de Mouro at 40 to 60 mg/L CaCO₃, identical to the other Sintra towns on this site. The 50 mg/L shown is the midpoint. A 2026 SMAS zone report with 42 mg/L is consistent with it, but the report does not say which parishes are in that zone. Soft water rarely needs descaling.
Portuguese operators report "dureza total" in mg/L CaCO₃ to ERSAR.
Water data
| Total hardness | 50 mg/L |
|---|---|
| Utility | SMAS Sintra |
How Rio de Mouro compares
- Tap water in Rio de Mouro is 40 % softer than the median of the 77 cities we track in Portugal (83 mg/L).
- By hardness it ranks 56 of 77 in Portugal (1 = hardest); 21 % of these cities have softer water.
- In 14 it is number 15 of 19 cities; the regional median is 75 mg/L.
- Nearest city with clearly softer water: Vila Franca de Xira, 36 km away (15 mg/L).
- Nearest city with clearly harder water: São Domingos de Rana, 7 km away (108 mg/L).
Ranking of the hardest and softest water in Portugal →
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 Rio de Mouro
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 3 °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 Rio de Mouro water hard or soft?
It is soft: 50 mg/L as CaCO₃ (2.9 gpg, 2.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Rio de Mouro 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 Rio de Mouro water?
2.9 gpg, equal to 2.8 °dH, 5 °fH or 50 mg/L calcium carbonate.
What dishwasher salt setting should I use in Rio de Mouro?
For 50 mg/L (2.8 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Rio de Mouro?
No. With soft water a softener adds nothing.
Source
Source: SMAS Sintra - Dureza por freguesia (table dated 06/06/2024) (2024-06). Method: computed from supplier's calcium and magnesium. SMAS Sintra - Dureza por freguesia (table dated 06/06/2024) · Outdated figure? Tell us