Product review (4 stars): works the best so far
This is the 4th humidifer I have had in my childrens room.  The room is very large and most humidifers are not strong enough.  These filters are the best replacement filters I have been able to find.  The bacteria build up is unfortunately a problem with all the humidifers I have found.  Using Holmes S1708 Bacteriostat for Cool Mist Humidifiers has seemed to resolve that issue and actually helped the filter last longer.