Water hardness in Stouffville
318 mg/L very hard
Tap water in Stouffville is very hard: 318 mg/L (18.6 gpg · 17.8 °dH · 31.8 °fH).
Source: York Region, Drinking Water Quality and Monitoring (2026 Q2 average hardness) (2026-06) · data checked 2026-10-20
Stouffville is part of York Region, but its supply is local groundwater, which is why it reads much harder than most of the region. The Q2 2026 average is 318 mg/L as CaCO3, with no range published. Scale builds up fast, and softeners are common.
Health Canada: hardness above 200 mg/L is considered poor but tolerable; above 500 mg/L unacceptable.
Water data
| Total hardness | 318 mg/L |
|---|---|
| Utility | York Region |
How Stouffville compares
- Tap water in Stouffville is 214 % harder than the median of the 254 cities we track in Canada (101 mg/L).
- By hardness it ranks 18 of 254 in Canada (1 = hardest); 93 % of these cities have softer water.
- In Ontario it is number 17 of 120 cities; the regional median is 124 mg/L.
- Nearest city with clearly softer water: Ballantrae, 8 km away (205 mg/L).
- Nearest city with clearly harder water: Fergus, 95 km away (519 mg/L).
Ranking of the hardest and softest water in Canada →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Stouffville
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 18 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| LG | H3 |
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 Stouffville water hard or soft?
It is very hard: 318 mg/L as CaCO₃ (18.6 gpg, 17.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Stouffville 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 Stouffville water?
18.6 gpg, equal to 17.8 °dH, 31.8 °fH or 318 mg/L calcium carbonate.
What dishwasher salt setting should I use in Stouffville?
For 318 mg/L (17.8 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Stouffville?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: York Region, Drinking Water Quality and Monitoring (2026 Q2 average hardness) (2026-06). Method: figure published by the water supplier. York Region, Drinking Water Quality and Monitoring (2026 Q2 average hardness) · Outdated figure? Tell us