Water hardness in Duas Barras
50 mg/L soft
Tap water in Duas Barras is soft: 50 mg/L (2.9 gpg · 2.8 °dH · 5 °fH).
Source: Ministério da Saúde, SISAGUA – controle semestral (Aguas Do Rio 1 Spe Sa), CC BY-ND 3.0 (2026) · data checked 2026-10-20
Range across supply zones: 14–86 mg/L.
Tap water in Duas Barras, Rio de Janeiro, is supplied by Aguas Do Rio 1 Spe Sa. The published figure is 50.4 milligrams per litre of calcium carbonate (soft), with readings from 14.1 to 85.8, so hardness varies between samples. Source: Ministry of Health SISAGUA semiannual control data, 2026; it does not state the water source.
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 | 50 mg/L |
|---|---|
| Utility | Aguas Do Rio 1 Spe Sa |
How Duas Barras compares
- Tap water in Duas Barras is 19 % harder than the median of the 1915 cities we track in Brazil (43 mg/L).
- By hardness it ranks 799 of 1915 in Brazil (1 = hardest); 58 % of these cities have softer water.
- In Rio de Janeiro it is number 5 of 44 cities; the regional median is 14 mg/L.
- Nearest city with clearly softer water: Sumidouro, 16 km away (6 mg/L).
- Nearest city with clearly harder water: Silva Jardim, 56 km away (78 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 Duas Barras
| 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 Duas Barras 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 Duas Barras 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 Duas Barras 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 Duas Barras?
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 Duas Barras?
No. With soft water a softener adds nothing.
Source
Source: Ministério da Saúde, SISAGUA – controle semestral (Aguas Do Rio 1 Spe Sa), CC BY-ND 3.0 (2026). Method: figure published by the water supplier. Ministério da Saúde, SISAGUA – controle semestral (Aguas Do Rio 1 Spe Sa), CC BY-ND 3.0 · Outdated figure? Tell us