Six months is a common starting interval for clean municipal water, but well water or heavy sediment can require much more frequent replacement. Pressure drop is often a better signal than the calendar.
Typical intervals
Many whole-house brands recommend roughly 6 months for standard sediment prefilters. SpringWell commonly lists up to around 6 months for its 5-micron cartridge.
Micron rating affects lifespan
Finer cartridges capture smaller particles but can clog faster. Using a 1-micron filter where 5 or 20 microns would be enough can create unnecessary maintenance.
Watch pressure drop
A loaded prefilter restricts flow. If household pressure falls and returns after replacement, the filter was likely overdue.
Well-water systems
Heavy sand, rust or oxidized iron can require staged sediment filtration rather than one fine cartridge.