Product review (4 stars): Don't replace your moldy filter, clean it.
Works as advertised but as with the first filter, the second one started being moldy about 3 weeks after installing. The solution I came up with was to soak the filter in a 5 gallon bucket with 1 oz of bleach with water and let soak for 5 minutes. Empty and refill bucket with fresh water, soaking for a few minutes. Empty and repeat with fresh water a second time. At this point you have a filter free of mold and ready for humidifying your home. I am hoping to keep the same filter for the winter season without having to buy a new one once a month.