Product review (1 stars): Poor quality filters...
First of all, there is not a blue pre filter on any of the ones I've received as part of the subscription plan.  Second, these last at most 2-3 weeks, even by following some of the tips on the reviews/comments by extending the life of the filter.  It seems as if the quality of the filters have just gotten worse over time.  Granted the prices do seem to reflect the changes.  The filters started at $15 bucks about 2 years ago but lasted around 1-2 months.  I've tried to make this work but having to replace the filters so frequently and having to clean the entire humidifier every few weeks... I'm done.  At this point, I've cancelled my subscription (have had this humidifier running for almost 2 years) and will be selling the humidifier and purchasing one that doesn't need a filter.