Refill granules (3 Pack) A7533
The 3 packs of granules enables easy refills of the demineralization cartridge
Easy replacement of the granules of demineralization cartridge A7531
For water mist without mineral or limescale
Enough for 3 granules changes
Replace granules every 2–3 months, or more frequently in areas with hard water
Use: for all ultrasonic humidifiers except the 7146 Travel
Its not rocket science, it will require steady hand a little bit of time. Cheaper to refill than to keep replacing filters. Happy overall.