Water guide · Updated September 2026
Planning Filter Replacement and Maintenance
Maintenance is where water treatment either delivers for years or quietly stops working. Intervals depend on your water and your usage — not on a number printed on a box.
Why 'every six months' is not an answer
Capacity is consumed by volume and by what the media is removing. A household of two on low-sediment municipal water and a household of six on a well with visible sediment will not share an interval, even with identical equipment.
Signs a stage is due
- Taste or odor returning at treated fixtures.
- Noticeable flow or pressure reduction, especially after a sediment stage.
- Spotting or scale reappearing where a softener previously handled it.
- RO output slowing or the storage tank refilling more slowly.
What a service visit should cover
- Correct cartridge or media specification for the housing and application.
- Housing, O-ring and fitting inspection.
- Pressure and flow check before and after.
- Bypass and shut-off operation.
- Softener settings and salt condition, including checking for bridging.
- Backwash and drain performance on media tanks.
- Recorded service date and the next expected interval.
Keeping ownership predictable
Ask for the maintenance expectation in writing before you buy, keep the model and cartridge specifications with your records, and note anything that changes between visits. Those three habits prevent most avoidable water treatment expense.
Sources consulted
- NSF — Water Treatment Device Certification — checked 2026-09-16
- US EPA — Drinking Water Requirements and Regulations — checked 2026-09-16
Primary sources are cited for general water quality and regulatory context. Nothing here is a statement about your specific property's water.
Related pages
Let's find the right starting point for your water.
Tell us about the property and what you have noticed. We will confirm the water supply, explain what information is needed, and outline suitable options in writing.