About 125 mg/L from Lake Ontario. Unremarkable water — but a whole town's worth of water heaters aged together.
Free 10-minute test at your tap. No obligation, no sales pitch.
Hardness is dissolved calcium and magnesium. Past about 120 mg/L it starts quietly costing you — in scale, in soap, and in appliances that die early.
Published municipal averages. Actual hardness shifts by pressure zone and season — an on-site test is the only way to know yours.
It is not dramatic and it is not an emergency. It is a slow efficiency loss on every heated surface in the building — the water heater first, because it runs hottest and you never see inside it.
Ajax is unremarkable water in a very particular kind of housing stock.
Durham draws from Lake Ontario and delivers around 125 mg/L across its lakeshore municipalities, so the hardness itself is moderate and consistent — nothing like what the groundwater communities to the north contend with.
What makes Ajax distinctive is how much of it was built at the same time. The town grew rapidly through the 1990s and 2000s, which means an unusually large number of homes reached water-heater replacement age within a few years of one another, and a great many of those replacements were high-efficiency or tankless units rather than like-for-like tanks.
Those are precisely the systems where 125 mg/L stops being academic. They run hotter, have tighter heat-exchanger passages, and register scale as a fault code rather than as a gradual loss of performance you can ignore for another winter.
The practical marker is simple. If your Ajax home is on its second water heater and the replacement is tankless or high-efficiency, that is the point at which softening starts paying for itself — not because the water changed, but because what it now has to pass through did.
A metered softener on the main, sized to your actual hardness rather than to a regional average, and a reverse-osmosis unit under the kitchen sink if you want drinking-grade water at the tap. Municipal supply arrives treated, so iron removal is not usually part of it.
L1S, L1T, L1Z
Ion exchange, the whole-home schematic and the well-water treatment order are laid out in detail on the main page — the science is the same everywhere, only the numbers change.
Most homes need one of the first two. If you're on a well, you need the third and it needs a water sample before anyone can quote it honestly.
For municipal supply on lake water. Takes the calcium out before it reaches anything.
Softened water everywhere, plus reverse osmosis at the kitchen tap and the fridge line.
Caledon, King, Uxbridge, Halton Hills, north Durham. Quoted after a lab sample, never before.
Optional service plan at from $14/month — annual filter changes, UV lamp replacement, yearly check. Cancel whenever. It isn't required to keep your warranty.
The national providers rent softeners at $30–$48 a month with no end date. Move the sliders and find the month where renting overtakes simply buying the thing.
Rental range reflects published 2026 GTA rates. Purchase range reflects installed market pricing. Salt and servicing excluded — you pay those either way.
| Outright | Typical rental | |
|---|---|---|
| Who owns the equipment | You do, on day one | They do, permanently |
| Contract length | None | Commonly 5–10 years |
| Cost after year ten | No monthly fee | Still $30–$48 every month |
| Repairs and service | 10-year parts typical. Service calls flat-rate after that. | Included — for as long as you keep paying. |
| Cancelling early | Nothing to cancel | Buyout terms apply |
| When you sell the house | Transfers with the home | Buyer assumes it, or you settle |
| Registration against title | Never | Banned in Ontario since 2024 |
| How you get a price | It's on this page | In-home appointment |
Pick a window. We confirm by text, not from a call centre.
Hardness, iron and pH, measured on site in about ten minutes.
Usually about three hours. Drain, bypass and disposal of the old unit included.
Paid once. Stays with the house when you sell it.
Ajax water measures about 125 mg/L, which is 7.3 grains per gallon — classified hard. Supply: Lake Ontario. Figures from Durham Region annual water quality report. Actual hardness varies by pressure zone and season, so an on-site test is the only way to know yours exactly.
At 125 mg/L it is a judgement call rather than an emergency. The clearest case is a home with a modern high-efficiency or tankless water heater, which has tighter passages and far less tolerance for scale than the tanks they replaced.
from $2,195 installed, or from $3,290 with reverse osmosis drinking water at the kitchen tap. These are starting prices — the final figure depends on the equipment and the install, and you get it in writing before any work begins. No in-home quote required to see a number.
You own it outright from the day it is installed. There is no monthly rental, no contract term, and nothing registered against your home. It transfers with the house when you sell.
Ten minutes at your tap. Hardness, iron and pH measured on the spot, a straight answer, and a price you already saw on this page.
No obligation, no sales pitch, and nobody stays for coffee.
We'll text you within one business day to confirm a window. Nothing is booked until you reply.