Product review (2 stars): new filter gets moldy quickly
Purchased the filter to replace my old moldy filter.  Had this one a few months, and within 6 weeks or so, I started to see black spots.  Can't remember whether the first filter was began to mold that early.  Relative to other humidifiers that I have previously owned, this one requires constant maintenance.  And, to have a ~$15 filter mold within such a short time, well, when this filter goes, I'll be purchasing a different unit altogether.