Water hardness in Potengi
139 mg/L hard
Tap water in Potengi is hard: 139 mg/L (8.1 gpg · 7.8 °dH · 13.9 °fH).
Source: Ministério da Saúde, SISAGUA – controle semestral (Companhia De Agua E Esgoto Do Ceara), CC BY-ND 3.0 (2025) · data checked 2026-10-20
Range across supply zones: 96–146 mg/L.
Potengi, in Ceará, is served by Companhia De Agua E Esgoto Do Ceara. Reported hardness is 139.3 mg/L CaCO₃, ranging from 95.7 to 145.6 mg/L, which places it in the hard category. Limescale on kettles and fixtures is a likely consequence (SISAGUA, 2025).
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 | 139 mg/L |
|---|---|
| Utility | Companhia De Agua E Esgoto Do Ceara |
How Potengi compares
- Tap water in Potengi is 228 % harder than the median of the 1915 cities we track in Brazil (43 mg/L).
- By hardness it ranks 78 of 1915 in Brazil (1 = hardest); 96 % of these cities have softer water.
- In Ceará it is number 15 of 47 cities; the regional median is 115 mg/L.
- Nearest city with clearly softer water: Assaré, 28 km away (110 mg/L).
- Nearest city with clearly harder water: Salitre, 30 km away (365 mg/L).
Ranking of the hardest and softest water in Brazil →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Potengi
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 8 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S1 |
| LG | H2 |
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 Potengi water hard or soft?
It is hard: 139 mg/L as CaCO₃ (8.1 gpg, 7.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Potengi 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 Potengi water?
8.1 gpg, equal to 7.8 °dH, 13.9 °fH or 139 mg/L calcium carbonate.
What dishwasher salt setting should I use in Potengi?
For 139 mg/L (7.8 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Potengi?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Ministério da Saúde, SISAGUA – controle semestral (Companhia De Agua E Esgoto Do Ceara), CC BY-ND 3.0 (2025). Method: figure published by the water supplier. Ministério da Saúde, SISAGUA – controle semestral (Companhia De Agua E Esgoto Do Ceara), CC BY-ND 3.0 · Outdated figure? Tell us