Product review (1 stars): Mold Growth occurred on this filter
I'm not sure how often one is supposed to change out a humidifier filter, but I usually swap them out twice a year -- as we don't use the humidifier regularly -- only when my kids are getting bloody noses or sore throats. We live in a dry climate with very low humidity, so having a humidifier is a good idea, even though we are not religious about using it.

I currently have two kids that have had headaches and stuffy noses, so I decided to turn the humidifier back on in their bedroom that they share. Usually I have to change the water every morning, but it wasn't sucking up the water. I went to change the filter, and as you can see by the photo -- the filter was full of dust, mold, and some other black growth. I checked my Amazon order history, and it had been 6 months since I first installed that filter.

So perhaps I waited too long to change the filter, but the product description does state that

"The Honeywell replacement wick filter is designed to prevent any type of growth of mold, fungus, algae, and bacteria."

There was definitely mold -- and lots of it, along with other stuff growing on this filter. It did not prevent the growth of these unwanted items in my Honeywell germ free humidifier.

I've used this same brand of filter in the past without any issues. I'm hoping that by replacing the moldy filter and deep cleaning the humidifier that the two kids who share the bedroom that the humidifier is in will recover quickly from their congestion and headaches. No one should be breathing mold like that. I did however like the price on this filter as it was less than the Honeywell Brand, but I am going to go back to using the Honeywell Brand filters because I cannot be exposing my children to mold like this.