Replacement Water Filter Guide

Replacement filters are a multi-billion dollar aftermarket — and a significant portion of what's sold on Amazon and third-party sites is counterfeit, underperforming, or mismatched to your system. The guides below cover how often to actually replace each filter type, how to spot counterfeit media, whether OEM replacements are worth the premium over third-party options, and which generic filters have independent testing data to back up their claims.