Product review (3 stars): You get what you pay for
The filter was priced fairly, and the box did say Honeywell (it wasn't a knock-off as some other reviews indicated it might be). I used the filter with a Pro-tec cartridge last winter and didn't change the filter once. In fact, I never even looked at it until it was time to set it up again this winter. That's when I realized it was pretty moldy and I should buy a new one. I received the new filter on Dec. 22 - it didn't even last me a month!!!

The only thing I did differently this time around was TRY to take better care of the filter to extend its life...because the filter arrived before the protec cartridge (both of which I ordered on Amazon) I used a drop of bleach in the water tanks. The mist had a bleach odor, which didn't bother me, but my boyfriend was concerned about our newborn breathing in the chemical - so I quit using bleach when the protect cartridge arrived. I also flipped the filter everyday, so the top part (which tended to dry out) stayed moist. Within a few days of the Protect cartridge and no bleach, the filter started to reek of mold and then it actually began to fall apart. The filter was crumbling and stunk. I just threw it out and am back online to order again.

What have I learned: While my humidifier kicks butt and keeps the entire upstairs area moist in the winter, the amount of time, energy and money I spend in filters and protect cartridges just doesn't make it worthwhile. I could buy three cheapo cool-mist humidifiers, with their itty bitty filters and wash them each once a week - and that's still less work daily! ...not to mention a heck of a lot cheaper!