A water filter only works while its media has capacity left. Change it on time and the system performs like new. Leave it too long and you lose most of what you paid for, and sometimes gain new problems. Here's what to expect.
Typical intervals
- Whole house sediment cartridges: every 6 to 12 months. Sooner on tank or bore water.
- Whole house carbon/KDF cartridges: every 6 to 12 months, depending on household size and chlorine levels.
- RO pre- and post-filters: every 6 to 12 months.
- RO membrane: roughly every 2 to 4 years.
Those ranges are wide for a reason. A couple on town water in a townhouse might stretch to the full 12 months. A family of six on a rainwater tank after a dusty summer might need the sediment cartridge changed well before that.
Signs your filters are due
- Pressure drops gradually. A clogged sediment cartridge restricts water to the whole house.
- The chlorine taste comes back. Carbon is exhausted.
- Scale reappears on glass, taps or the kettle.
- RO water tastes flat or slightly salty, or the tank refills slowly.
What happens if you leave them in
An overdue sediment cartridge doesn't just stop filtering. It becomes a bottleneck that cuts flow to every shower and tap. Spent carbon can stop holding on to what it has trapped. In RO units, tired pre-filters let chlorine through to the membrane and shorten its life, which turns a cheap cartridge change into a more expensive membrane replacement.
DIY or technician?
Most of the cartridges we supply twist out without tools, and a DIY change takes about 15 minutes with the bypass valve closed. If you'd rather not, a technician visit includes the change plus a pressure, flow and leak check and a sanitise of the housings.
Never guess again
We keep a record of every system we install and email you before each change is due. Pure Forge owners can order replacements or book a change-out any time. If your system came from someone else, send a photo and we'll identify the cartridges.