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By Alex Capitan · Updated May 2026 · 6 min read

How Often to Replace Water Filters — Real Schedule by Type

Filter replacement schedules vary widely by type. Here’s the real data from manufacturer specs and NSF certification requirements.

⚡ Quick reference

· Pitcher filters: every 2 months or 40 gallons

· Under-sink: every 6–12 months

· Reverse osmosis: membranes every 2–3 years, pre-filters every 6–12 months

· Whole house: every 6–12 months (sediment), every 3–5 years (carbon)

Replacement schedule by filter type

Filter type	Replace every	Or by gallons	Annual cost
Pitcher (Brita)	2 months	40 gallons	~$40
Pitcher (Clearly Filtered)	4 months	100 gallons	~$60
Under-sink carbon	6–12 months	500–1,000 gal	~$50–80
RO pre-filters	6–12 months	—	~$30–50
RO membrane	2–3 years	—	~$30–60
Whole house sediment	6–12 months	—	~$20–40
Whole house carbon (SpringWell)	~5 years	1,000,000 gal	~$120

Signs your filter needs replacing

Don’t wait for obvious signs — most filters lose effectiveness before you notice any change in taste or smell. But here are warning signs that your filter is overdue:

·Water tastes or smells like chlorine again

·Flow rate has slowed noticeably

·Filter indicator light is red or flashing

·You’ve exceeded the recommended gallon count

·More than 12 months since last replacement

Does an old filter make water worse?

Yes — an expired carbon filter can release captured contaminants back into your water, a process called channeling. This means an old filter can actually make water quality worse than no filter at all.

Replace filters on schedule. Set a calendar reminder or use the filter’s indicator if it has one.

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