Product review (4 stars): Excellent but hard to dispense
Even with use of less than suggested, this keeps filters cleaner, longer than any other product I have found.  Measuring one capfull was hard for me so, I have emptied the contents into a tight sealing wide mouth container (cottage cheese container), and use a small syringe (no needle) to easily insert the equivalent dose into my humidifier tank.  I do not have the concerns about chemical injestion that others do.