The filter is the expensive part. These are the small items that make owning one easier — measuring what your filter is actually doing, changing cartridges without a fight, and connecting a fridge in the first place. Everything here ships within Canada, so no duties or brokerage fees.
Measuring your water
TDS meter
Reads total dissolved solids in ppm. Genuinely useful if you run reverse osmosis — it shows the membrane failing months before taste does. Less useful on carbon filters, which barely change TDS.
Bacteria test kit
Detects E. coli and coliform. The single most important test if you are on a private well, and worth running twice a year however clear the water looks.
Before buying either
On municipal water your city already publishes a fuller analysis than any home kit produces, for free.
Changing cartridges
Filter housing wrench
Under-sink and reverse osmosis housings tighten over months and can be genuinely stuck by the time you want them open. The right wrench costs less than the plumber you would otherwise call.
Inline fridge filter
Fits the water line rather than inside the fridge. Useful for older fridges with no internal housing, or as a sediment pre-filter ahead of an ice maker.
Find your cartridge
Order by part number, not brand. Our brand pages list the numbers each manufacturer uses.
Installing and protecting
Ice maker line kit
25 feet of tubing with valve and quarter-inch fittings — what you need to connect a fridge where no water line exists. Check your local plumbing code first; saddle valves are restricted in some jurisdictions.
Leak detectors
Every under-sink filter is a connection that can weep. A sensor under the cabinet catches it before the floor does. The cheapest insurance on this page.
Fitting it yourself?
What is involved, the tools needed, and when to call a plumber instead.
One honest note on TDS meters. They are often bought expecting to prove a carbon filter is working. They will not — carbon removes chlorine and organics, which barely register as dissolved solids. A TDS reading that is unchanged after filtering is normal and does not mean the filter has failed. TDS meters are for reverse osmosis.
Prices checked August 2026 and shown live on Amazon. Availability may change.
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