Product review (2 stars): Clogging issue
Replacing the granules is not a big deal. It takes a few minutes. You can either use the cup provided or pour it from package.

The issue is  the humidifier stop even though there is still water inside. I do notice the granules does not fill up the cartridge.

If you have hard water at home, I suggest you get another humidifier with built in filter so it does not spew white dust all over the house. I have a air purifier at home and it always goes red  indicating bad air quality every time I turn on this humidifier even with brand new granules.