Product review (3 stars): Ok filter
The product has a long life only if you keep it in use.  So keep the water reservoir full.  If the unit runs out of water and the product drys out then its lifespan dramatically shortens.  By shortens, once it dries out it seems to become very susceptible to mold and/or fungus growth.  The product is made with a protective coating to prevent this but it must become damaged when the filter dries out.