All you need to do is call the manufacturer and ask them to send out a bottle of solution that will eliminate the dust (caused by minerals) in the humidifier.
Add one capful of the solution to every 2 gallons of water or so. How much to use depends on how hard your water is. Your village or city can provide that information to you.
IF you have a private well, be thankful that you've experienced the rapid brown element as you NEED to have the well shocked.
My humidifier is a Holmes and I received and started using it the same day as a big snowfall. I thought I was hallucinating all this dust! NOT! And what a BEAST it is to get the dust out of puter keys, TV's, etc.
Since Holmes sent me the solution, I've not seen a SPEC of that white dust.
Hope this helps!