Product review (1 stars): False economy... buy the OEM!
I purchased the "replacement" filter with no blue covering from Filters Now. First, and it is unsubstantiated I admit, it does not appear to be made by Honeywell as it is shipped with no label in a plain box. I could be wrong though. Regardless, even if it were made by NASA for the space shuttle, the fact remains that it is lousy!

I live in Arizona and use the humidifier for a small apartment. Within two hours of use (on high or medium setting) the top half of the filter that is not immersed in water is totally dry. Apparently the "wicking" action of the filter is so poor that the very act of using it (by passing air through it to humidify air) drys the filter out such that it becomes nearly useless.

The OEM filter with the blue wrapping worked HUGELY better. Same apartment, same machine, same season, same outside relative humidity. With the "blue" filter, humidity averaged 40% . With this one, we can barely keep it at 25% and this is flipping it and rinsing it every two or three hours. The other way to compare is the tank used to empty in less than 12 hours and now is half full after 12 hours of use.

I understand some people claim the blue gets mildew, but at least that is a sign that it actually stays wet! I never had mildew, but I had humidity. I would never buy this one again. Total waste of money. Should have built my own from an old sweat sock for all the good it does.