Product review (5 stars): best filter for this machine
I have had this machine for six years.  YES, the same machine and just bought another one.  I have tried several different filters  that  were less expensive initially, thinking I would save money, but they didn't last long and required more maintenance.  This is the longest lasting filter I have used.  Hints on maintenance:  I flip the filter at each refill, usually once every day or two.  This doesn't take much effort and really lengthens the life of the filter.  Once a week I take the filter to the sink and rinse it in several changes of water to remove the salt build-up I have from my softened water.  I also take the base of the machine and wipe out any grime that collects there. Mine last three to four months or more with maximum output to raise my humidity level to what I want it to be.