Product review (3 stars): OK I guess
Does not keep lime scale off warm mist humidifiers...well, it seems to help, but not much. I've been using this a long time for borderline hard water and I'm afraid that without something, the humidifiers would die within a week or 2, instead of a year or 2.

With the newer Vicks Humidifier it seems to help a bit better. Although the Vicks has those little scale-absorbing pads too.

Guess you just have to try it for yourself...sorry.