Product review (4 stars): Just read the bottom of the filter door and found out what to look for as far as usage coloration on the filter and when would b
These filters are large but not too difficult to install.  Just read the bottom of the filter door and found out what
to look for as far as usage coloration on the filter and when would be best to replace. I'm replacing the original filter
after 35 days of usage and also cleaning the bottom of the humidifier.  I use the bacteriostat and PC-1 tank cleaning
cartridge every time I refill the water tanks.  Seems to work.  The tank was clean and did not have slime or black
bacteria.