How do you maintain a water filtration system?
Updated August 2026
A water filtration system lives or dies on its swap schedule: whole-house sediment and carbon cartridges every 3 to 6 months, reverse-osmosis membranes every 2 to 3 years, and a sanitize of the housings once a year. Miss the cartridge changes and a clogged filter does the opposite of its job, choking your water pressure while passing unfiltered water straight through. Stay on top of it and the system itself lasts 10 to 15 years.
| Task | Interval | Effort |
|---|---|---|
| Replace whole-house sediment and carbon cartridges | 3–6 months | $20–60 · DIY |
| Watch for a pressure drop as the change-it-now signal | Monthly glance | 1 min · DIY |
| Task | Interval | Effort |
|---|---|---|
| Sanitize housings with bleach solution at a cartridge change | Yearly | 30 min · DIY |
| Replace the UV lamp on UV disinfection systems | Yearly | $50–120 · DIY |
| Task | Interval | Effort |
|---|---|---|
| Replace the reverse-osmosis membrane | 2–3 years | $50–120 · DIY |
| Replace RO pre- and post-filters on the maker schedule | 6–12 months | $30–80 · DIY |
What neglect costs
Filters do not fail gracefully. A sediment cartridge left in past its window packs with silt until it strangles flow to a trickle, so the first sign is weak pressure at every tap downstream. Carbon is worse: once its capacity is spent it stops adsorbing chlorine and contaminants and can even shed captured gunk back into the water, so you are drinking through a dirty sponge. A UV system with a burned-out lamp looks fine but disinfects nothing. The parts are $20 to $120; the cost of skipping them is unfiltered water and a system that clogs itself toward an early end of life.
Leave these to a pro
Cartridge and membrane changes are all DIY: shut the bypass, unscrew the housing with the supplied wrench, and swap. Bring in a plumber or water-treatment tech for the initial install, for re-plumbing a bypass loop, or when a water test shows the system is not keeping up and you need to resize or add a stage. A service call runs about $100 to $200. On a well, pair the filter schedule with regular water testing, since what is actually in the water dictates which cartridges you need and how fast they load up.
This whole checklist ships as reminders in OnOtto: every task above, on the right schedule for your home, snooze-proof.
Load this checklist as remindersFrequently asked questions
How often do I change a whole-house water filter?
Every 3 to 6 months for standard sediment and carbon cartridges, though the real trigger is pressure. When flow at the faucets noticeably drops, the filter is loaded and due, whatever the calendar says. Heavy sediment or well water can mean monthly changes; clean city water can stretch toward six months. Mark the change date on the housing so you are not guessing. The whole-house filter interval page has the specifics.
How long do reverse osmosis filters last?
The pre-filters and post-filter last 6 to 12 months, and the RO membrane itself 2 to 3 years, longer if the pre-filters are changed on time to protect it. Hard water and heavy use shorten membrane life. A drop in output or a return of bad taste means the membrane is spent. See the RO filter interval page for the staged schedule.
How often does a UV water filter bulb need replacing?
Every 12 months, even if it still glows. A UV lamp keeps lighting long after its output has faded below the dose that actually kills bacteria, so it fails silently while looking perfectly fine. Change it yearly on schedule, replace the quartz sleeve every few years, and never judge it by whether the light is on. Well systems relying on UV should never skip this. The UV bulb interval page explains why.