Extend the life of your humidifier with Pure Enrichment's Humidifier Descaling Cartridge Filter. This easy-to-install filter helps reduce mineral buildup and white dust from hard tap water in your humidifier's water tank. For optimal performance, we recommend replacing your humidifier filter every 2-3 months. Our filter is designed to work with the Pure Enrichment HUME Sense Top Fill Humidifier (PEHUTRB-W). Humidifier sold separately.