A typical household RO membrane often lasts about 2–3 years, but poor feed water, chlorine exposure, scaling or neglected prefilters can shorten that substantially. Track rejection performance and follow the exact system schedule.
Typical lifespan
Many residential RO manufacturers publish membrane intervals around 18–36 months. Frizzlife lists roughly 24 months on several PD-series membranes, while exact intervals vary by model and water conditions.
What shortens membrane life
Hardness scale, iron, manganese, chlorine breakthrough and high feed TDS can all accelerate performance decline. Pretreatment and timely carbon-filter replacement matter.
How to tell when it is failing
A sustained drop in rejection percentage or rising permeate TDS can indicate membrane decline. Use TDS as a trend tool rather than as a contaminant safety test.
Do not replace on calendar alone
If a membrane still performs well and the manufacturer does not require a fixed change interval, condition-based replacement can avoid unnecessary cost.