Water Hardness Atlas ZIP / postcode

Water hardness in Itaguaí

8 mg/L soft

Tap water in Itaguaí is soft: 8 mg/L (0.4 gpg · 0.4 °dH · 0.8 °fH).

<6060–120120–180>180 mg/L

Source: Ministério da Saúde, SISAGUA – controle semestral (Rio Saneamento Bl3 Sa), CC BY-ND 3.0 (2026) · data checked 2026-10-20

Itaguaí is served by a private concessionaire in the former Cedae area of Rio de Janeiro state, and the sources checked do not name its intake. Records for 2026 give a median of 7.7 mg/L CaCO₃ without a published range. Water this soft rarely forms visible scale, so a softener is not needed and detergent can be dosed lightly.

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 hardness8 mg/L
UtilityRio Saneamento Bl3 Sa

How Itaguaí compares

Ranking of the hardest and softest water in Brazil →

What it means at home

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 Itaguaí

BrandSetting for this water
BoschH00
Miele1 °dH
AEG / Electrolux1
Beko1st
HooverS0
LGH0

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 Itaguaí water hard or soft?

It is soft: 8 mg/L as CaCO₃ (0.4 gpg, 0.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.

Is tap water in Itaguaí 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 Itaguaí water?

0.4 gpg, equal to 0.4 °dH, 0.8 °fH or 8 mg/L calcium carbonate.

What dishwasher salt setting should I use in Itaguaí?

For 8 mg/L (0.4 °dH) check your manufacturer's table: level 0–1, usually no salt.

Do I need a water softener in Itaguaí?

No. With soft water a softener adds nothing.

Source

Source: Ministério da Saúde, SISAGUA – controle semestral (Rio Saneamento Bl3 Sa), CC BY-ND 3.0 (2026). Method: figure published by the water supplier. Ministério da Saúde, SISAGUA – controle semestral (Rio Saneamento Bl3 Sa), CC BY-ND 3.0 · Outdated figure? Tell us

Nearby cities

Paracambi11 mg/LQueimados6 mg/LJaperi14 mg/LMesquita14 mg/LNova Iguaçu13 mg/LNilópolis27 mg/L
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