Water hardness in São Sebastião
5 mg/L soft
Tap water in São Sebastião is soft: 5 mg/L (0.3 gpg · 0.3 °dH · 0.5 °fH).
Source: Ministério da Saúde, SISAGUA – controle semestral (Companhia De Saneamento Basico Do Estado De Sao Paulo), CC BY-ND 3.0 (2026) · data checked 2026-10-20
Range across supply zones: 2–8 mg/L.
Sabesp reports 5.0 mg/L CaCO₃ for São Sebastião on the São Paulo coast, with samples between 2.0 and 8.0 mg/L. This is among the softest water in the dataset. Scale is unlikely to form, and soap and detergent should lather easily. We have not verified the source water for this city.
Portaria GM/MS nº 888/2021 sets a maximum of 300 mg/L CaCO₃ for total hardness (dureza total); operators report it in mg/L to SISAGUA.
Water data
| Total hardness | 5 mg/L |
|---|---|
| Utility | Companhia De Saneamento Basico Do Estado De Sao Paulo |
How São Sebastião compares
- Tap water in São Sebastião is 88 % softer than the median of the 1915 cities we track in Brazil (43 mg/L).
- By hardness it ranks 1909 of 1915 in Brazil (1 = hardest); 0 % of these cities have softer water.
- In São Paulo it is number 526 of 530 cities; the regional median is 42 mg/L.
- Nearest city with clearly harder water: Paraibuna, 43 km away (23 mg/L).
Ranking of the hardest and softest water in Brazil →
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 São Sebastião
| 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 São Sebastião water hard or soft?
It is soft: 5 mg/L as CaCO₃ (0.3 gpg, 0.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in São Sebastião safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Portaria GM/MS nº 888/2021 sets a maximum of 300 mg/L CaCO₃ for total hardness (dureza total); operators report it in mg/L to SISAGUA.
How many grains per gallon is São Sebastião water?
0.3 gpg, equal to 0.3 °dH, 0.5 °fH or 5 mg/L calcium carbonate.
What dishwasher salt setting should I use in São Sebastião?
For 5 mg/L (0.3 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in São Sebastião?
No. With soft water a softener adds nothing.
Source
Source: Ministério da Saúde, SISAGUA – controle semestral (Companhia De Saneamento Basico Do Estado De Sao Paulo), CC BY-ND 3.0 (2026). Method: figure published by the water supplier. Ministério da Saúde, SISAGUA – controle semestral (Companhia De Saneamento Basico Do Estado De Sao Paulo), CC BY-ND 3.0 · Outdated figure? Tell us