Product review (5 stars): This works!
I was a little apprehensive at first when I thought about breathing in these chemicals along with the air that my humidifier would be pumping out.  But then I saw that you only need to use a tiny cap full for a gallon of water. Plus,  I thought about the mold and other nastiness that I could be breathing if I didn't use some kind of treatment (after looking at how disgusting my old filter was that I had just pulled out of there -  ick!) so I thought this was the better alternative.  It's making my filter last so much longer and the water has stayed clear after almost 3 months of use.