Alkaline cartridge
Stage 6 — restores alkaline balance to the water after reverse osmosis.
Cartridge prices are quoted on request — they move with each shipment, and we will not publish a number that is stale within weeks. We confirm it before any commitment, or it sits inside the annual service contract at a fixed price.
What this stage does
Sits after reverse osmosis and raises the pH that purification lowered, giving the water back some balance. It works slowly and is consumed slowly — which is why its life is two years rather than months.
How you know it is overdue
- A slightly sharp or sour edge to the water
- Two years have passed — and that is the real signal, because the change is gradual enough that you will not notice it day to day
Why a range and not one number?
Because what uses a cartridge up is the volume of water passing through it and what that water carries — not the calendar. A household of six gets through one faster than a household of two, and a tank collecting more sand shortens it further. We write the reading down at every visit, so by the second or third we know your home's actual rhythm instead of guessing.
Fits these systems
If your system is on this list, this is the right cartridge.
The rest of the set — RO kitchen filter cartridges
- PP sediment 5µEvery 4–6 months
- GAC carbonEvery 4–6 months
- CTO carbon blockEvery 4–6 months
- RO membraneEvery 4–6 months
- Post-carbon polishEvery 4–6 months
- Mineral cartridgeEvery 24 months