How Often Should You Really Replace Your Water Filter?

Every water filter has a use-by date, and it is earlier than most people assume. A cartridge that looks fine sitting in its housing can already be past the point where it is doing much work. Here is the actual schedule, by filter type, and why it is not a "whenever I remember" decision.

Sediment Filters: Every 6 Months

A 10 inch 1-micron sediment filter catches rust, sand, silt and fine dirt before it reaches the rest of your system. It is a physical barrier, not a chemical one, so it does not "run out" the way carbon does. It clogs. As it clogs, flow rate drops and pressure across the cartridge increases, which is exactly the point at which trapped particles can start breaking loose and passing through. Six months is the point most manufacturers, including ours, set as the ceiling for a standard residential household.

Carbon Filters: Every 6 Months

A carbon block filter works through adsorption, contaminants binding to the surface of the carbon media as water passes through. That surface area is finite. Once it is saturated, the filter stops removing chlorine, chloramine and taste and odour compounds, and in some cases can begin releasing what it has already captured back into the water. Six months is the standard interval for a residential carbon block under normal use.

Combined Systems: Every 6 to 12 Months, Depending on the Cartridge

If your setup uses a twin housing with separate sediment and carbon stages, both cartridges follow the 6-month rule and are worth changing together, which is exactly why we sell them as a combo set. If you have a single-housing system such as the Filtered Tap System (available in Silver Chrome and Matte Black), the combined cartridge is rated for a longer 12-month interval, reflecting the different media construction. Check which configuration you have before assuming either number applies.

Reverse Osmosis: Membrane Every 2 to 3 Years, Pre-Filters Every 6 to 12 Months

An RO system has more than one consumable. The membrane itself is the long-life component, typically good for two to three years under normal residential use. The carbon and sediment pre-filters that protect it wear out much faster and need replacing on the same 6 to 12 month cycle as a standalone carbon or sediment filter. Neglecting the pre-filters shortens the life of the membrane, which is the expensive part. Our RO replacement filter set covers the pre- and post-filter stages.

What Actually Happens If You Leave It Too Long

Nothing dramatic, at first. Flow slows. Taste and odour reduction quietly drops off. Eventually a saturated cartridge stops being a filter and becomes just another surface for bacteria to colonise, especially in the moist environment inside a housing that has not been serviced. None of this shows up by looking at the cartridge. It shows up in the water.

The Simplest Fix

Write the date on the housing when you install a new cartridge, or set a recurring reminder for 6 months out. If you would rather not think about it at all, browse the full replacement filter range and pick the set that matches your system.