Product review (3 stars): Stadler Form Demineralization Cartridge
If you own a Stadler Form humidifier that uses these cartridges, they are essential to reducing the white dust that forms in your household when using an ultrasonic humidifier. They do not clear up the problem entirely. Dusting is still necessary. The only thing better is going to the expense of purchasing or making your own distilled water. Secondly, the cartridge creates a slime-like residue in the water chamber of the humidifier that's another cleaning chore. These cartridges are not inexpensive (even at Amazon pricing)probably because of the nice plastic housing. Depending on the hardness of your water, and if you use your Stadler Form humidifier constantly, you will be spending between $90-180 a year on cartridges, a not insubstantial sum.