Water hardness in Resende
11 mg/L soft
Tap water in Resende is soft: 11 mg/L (0.6 gpg · 0.6 °dH · 1.1 °fH).
Source: Ministério da Saúde, SISAGUA – controle semestral (Aguas Das Agulhas Negras Sa), CC BY-ND 3.0 (2026) · data checked 2026-10-20
Range across supply zones: 3–24 mg/L.
Resende is supplied by a local operator; the sources checked do not name its intake. Records for 2026 give a median of 10.9 mg/L CaCO₃, with individual results from 2.6 to 23.6 mg/L. Check the utility's own report for your supply zone, since results can differ by address.
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 | 11 mg/L |
|---|---|
| Utility | Aguas Das Agulhas Negras Sa |
How Resende compares
- Tap water in Resende is 74 % softer than the median of the 1915 cities we track in Brazil (43 mg/L).
- By hardness it ranks 1790 of 1915 in Brazil (1 = hardest); 6 % of these cities have softer water.
- In Rio de Janeiro it is number 30 of 44 cities; the regional median is 14 mg/L.
- Nearest city with clearly softer water: Itaguaí, 82 km away (8 mg/L).
- Nearest city with clearly harder water: Arapeí, 25 km away (38 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 Resende
| 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 Resende water hard or soft?
It is soft: 11 mg/L as CaCO₃ (0.6 gpg, 0.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Resende 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 Resende water?
0.6 gpg, equal to 0.6 °dH, 1.1 °fH or 11 mg/L calcium carbonate.
What dishwasher salt setting should I use in Resende?
For 11 mg/L (0.6 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in Resende?
No. With soft water a softener adds nothing.
Source
Source: Ministério da Saúde, SISAGUA – controle semestral (Aguas Das Agulhas Negras Sa), CC BY-ND 3.0 (2026). Method: figure published by the water supplier. Ministério da Saúde, SISAGUA – controle semestral (Aguas Das Agulhas Negras Sa), CC BY-ND 3.0 · Outdated figure? Tell us