Product review (5 stars): Amazing stuff!
I live in New York, where we're snooty about our water, but I was replacing humidifier wicks every few weeks, making my humidifier an expensive proposition. This stuff makes wicks come back from the dead! If the wick gets dry because the water is used up, I re-soak it, turn it upside-down, and use about a teaspoon per gallon each time I refill the water. The little meter goes from the red zone back into the OK zone.