Product review (5 stars): Really helps improve filter life!
I bought this treatment for use in my Vornado humidifier.  Historically I had to change the filters about once every 6 weeks due to all the build up of bacteria/algae.  I use 1/2 capful in each of the two water tanks when I refill the humidifier.  I have not noticed any excessive foaming when I fill the tanks - I put the bacteriostatic treatment in first, then refill and return to the humidifier.  It is now been almost two months and the filters still look like new.  Barely any odor either from the treament.  Will save me a ton in replacement filters!