Product review (4 stars): Not exactly as I expected, but I'm a noob.
My humidifier was not humidifying the house enough and I confirmed the water was flowing. I looked at filter, having been recently replaced, and saw what I thought was buildup of deposits of the filter, so I ordered these new. When these filters arrived, I saw the same "coating" on the screen..so I have not replaced my filter as of yet till next heating season.
Still not sure why my humidifier is lacking though, oh, well.