Product review (1 stars): Complete garbage
Honestly, I find it hard to believe all the 4 and 5 star reviewers have had ZERO problems with the unit turning off prematurely (blinking empty) when there is still plenty of water in the tank.

I have tried the refill beads for two seasons now and I find it a major P.I.T.A. I don't mean the cartridge filling process, that's a no-brainer.

Here's the real problem... If you unscrew the cap from the filter and then turn the filter upside-down you will see fine mesh screens that cover the bottom of the filter. Well, on a DAILY basis the beads will flow down to the bottom of the filter and CLOG the screens. No water flow, no functioning humidifier.

At least twice a day I have to take the tank off the unit (usually half full or so of water), unscrew the cap, take the cartridge off the cap (hold it upside-down) and bang it on a counter top so that the screens are unclogged by the beads.

Next day... repeat.

I contacted Air-O-Swiss' customer support and the guy suggested I remove two tablespoons of the beads from the already filled cartridge -- no difference!

I refilled the cartridge a second time, but this time I left out two tablespoons of the "dry" beads (before the 24 hour soak)... no difference!

Also, these bead refills seem to spew the white powder all over everything much sooner than the factory-filled cartridges.

Sure, the refills save money, but cause a ton of frustration and daily maintenance.