Product review (5 stars): Just What I Needed
My humidifier was acting crazy -- the "add water" light was staying on, I couldn't control the gauges, and even when I ran it overnight, the water tanks never ran dry.  This went on for a couple weeks and I was convinced it was ready to be trashed, which annoyed me, because it was bought new only a couple years ago, and it was expensive.

One of the broken gauges indicated that the filter needed replacing, so even though I had just put in a new filter a couple months before, I decided to try that before dumping the expensive humidifier.  I ordered the filter through Amazon, and it arrived within a few days.

Opened the humidifier to replace the filter and nearly gagged.  I could't believe the moldy filter and brackish water.  I'd been breathing that?  Ugh.

I took out the old filter and tied it in a plastic bag so I could get rid of it without breathing any more of the mold in.  Wished I'd had a hazmat suit, or at least a mask.  Then I ran the new filter under some water for a minute or so, so that it would stretch over the drum when I replaced it.  Cleaned out the humidifier, put the new filter and fresh water in, and... miracle.  The gauges work, the water tanks empty, and the house isn't one big electric spark minefield.

The new filter was reasonably priced, arrived quickly, and saved me from having to buy a new humidifier.  So glad on all counts.