Water hardness in Renfrew
86 mg/L moderately hard
Tap water in Renfrew is moderately hard: 86 mg/L (5 gpg · 4.8 °dH · 8.6 °fH).
Source: Town of Renfrew, Water Treatment Annual Report 2025 (2025) · data checked 2026-11-05
Range across supply zones: 56–115 mg/L.
Renfrew's drinking water system is run for the town by the Ontario Clean Water Agency. The 2025 annual report gives a computed average of 85.7 mg/L as CaCO₃, with readings between 56.3 and 115.0 mg/L. That is moderate water, so light scale can build up on kettles and shower glass. The report does not describe the geology here, so we make no claim about it.
Health Canada: hardness above 200 mg/L is considered poor but tolerable; above 500 mg/L unacceptable.
Water data
| Total hardness | 86 mg/L |
|---|---|
| Utility | Town of Renfrew (drinking water system operated by Ontario Clean Water Agency) |
How Renfrew compares
- Tap water in Renfrew is 15 % softer than the median of the 254 cities we track in Canada (101 mg/L).
- By hardness it ranks 144 of 254 in Canada (1 = hardest); 43 % of these cities have softer water.
- In Ontario it is number 98 of 120 cities; the regional median is 124 mg/L.
- Nearest city with clearly softer water: Pembroke, 51 km away (12 mg/L).
- Nearest city with clearly harder water: Prescott, 124 km away (120 mg/L).
Ranking of the hardest and softest water in Canada →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Renfrew
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
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 Renfrew water hard or soft?
It is moderately hard: 86 mg/L as CaCO₃ (5 gpg, 4.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Renfrew safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Health Canada: hardness above 200 mg/L is considered poor but tolerable; above 500 mg/L unacceptable.
How many grains per gallon is Renfrew water?
5 gpg, equal to 4.8 °dH, 8.6 °fH or 86 mg/L calcium carbonate.
What dishwasher salt setting should I use in Renfrew?
For 86 mg/L (4.8 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Renfrew?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Town of Renfrew, Water Treatment Annual Report 2025 (2025). Method: computed from supplier's calcium and magnesium. Town of Renfrew, Water Treatment Annual Report 2025 · Outdated figure? Tell us