Two limits, whichever comes first
Cartridges are rated for a volume of water and for a period of time. A low-usage household typically reaches the time limit first, because media degrades whether or not water is flowing through it. A high-usage household reaches the volume limit first.
Signs a cartridge is due
- Noticeably reduced flow at the filtered tap
- Taste or odour returning
- A sediment cartridge that is visibly discoloured or loaded
- The stated interval has passed, regardless of appearance
Why overdue cartridges are a problem
A loaded sediment cartridge restricts flow throughout the system it feeds. Exhausted carbon media stops reducing what it was fitted to reduce, so the system continues to look like it is working while no longer doing so.
Keeping on top of it
- Write the installation date on the housing when the cartridge is fitted
- Set a calendar reminder for the stated interval
- Keep a spare cartridge on hand for the sizes you use
- Arrange a scheduled service if you would rather not track it yourself