How Often Should You Change a Water Filter? A Practical Guide

How often you need to change a water filter depends on the filter type, your water quality, and household usage. Here’s a practical guide to replacement intervals for every common filter type.

Browse our replacement cartridge range or see our guide: When to Replace Your Water Filter Cartridges.

Replacement Intervals by Filter Type

These are general guidelines. High-sediment water (bore, tank, or some regional supplies) will exhaust cartridges faster. Larger households use more water and will need more frequent replacement.

Factors That Affect Replacement Frequency

• Water quality: high sediment, chlorine, or contaminant loads exhaust cartridges faster
• Household size: more people = more water = faster cartridge exhaustion
• Filter capacity: larger-format cartridges (Big Blue 20") last longer than standard 10" cartridges
• Water source: bore and tank water typically requires more frequent replacement than town water

What Happens If You Don’t Replace Your Filter?

An exhausted filter provides little to no filtration — contaminants pass straight through. A clogged sediment cartridge reduces water pressure throughout the house and puts strain on pumps and appliances. In some cases, a heavily fouled filter can become a source of bacterial growth rather than protection against it.

Frequently Asked Questions