Quick take
The brand commonly positions cartridges around a 60–90 day replacement window. Use actual flow, local water quality and the manufacturer schedule rather than stretching the cartridge indefinitely.
Replacement interval
A two-to-three-month interval means four to six cartridges per year for a continuously used faucet.
What shortens life
High sediment, heavy daily use and source-water conditions can increase loading.
Cost per year
Annualize the one-time or subscription cartridge price before comparing Filterbaby with larger under-sink systems.
Certification wording
Do not treat component testing or lab results as equivalent to a formal finished-product NSF listing unless the exact model appears in the certifier directory.