Product review (5 stars): Must Have
Use with a 4 gallon humidifier, and really extends the life of the filters. Without this product I would be happy to make it 2-3 weeks with the firlters before they became extremely moldy and had to be replaced. With this I can stretch it to 2-3 months. Also keeps the humidifier itself much cleaner. This is a must have if you have a humidifier.