Product review (2 stars): My method for making these last longer.
They work great at first but after 2 weeks there is a little orange color and they start making the house smell like a fish tank.  I have two of these wemo humidifiers and wasn't about to spend $50 every 2 weeks to replace filters.  So I took them out filled up the sink with hot water and bleach and let them soak 15 to 30 min. Once I did drain and soak a second time.  Then carefully rinse them well and let them dry.  They turn completely white again, looking almost new, and are ready to put back into the humidifier.  I have done this a couple times and haven't had any issues but I would imagine I can only get away with doing that so many times before they are completely ruined.  But at least I get some extra life out of them without the house smelling like an aquarium.