Product review (5 stars): This Stuff Rocks!
I've purchased other humidifer water treatments fir warm mist humidifiers, but this one is really, really good.  I used the product as directed, started out with two capfulls, but had to increase it to three (our water is very hard) and that did the trick.  The buildup is minimal and wipes clean.  I use this water treatment with a Vicks warm mist humidifier.