Product review (1 stars): Filter Sleeve disintegrated!
After one week I noticed the water had a brownish tinge.  I thought I might have used tap water by accident, so I watched it a couple more days, making sure to use distilled water.  Finally I got the bright idea to check the filter.  When I took the center piece off of the humidifier, the filter sleeve was laying loose in the bottom pan (what was left of it, anyway).  Pieces of the sleeve were floating around.  I picked up the biggest piece of the sleeve and it crumbled further.

I wouldn't recommend this product to anyone.  I feel like I've been breathing pieces of disintegrated filter all week.