Product review (4 stars): works as advertised
i'm on my second wick filter at this point and have no problems with them. they do discolor a bit in my humidifier at the top end (turns to a brown color) but there is no smell or visible mildew, so it must just be some minerals in the tap water that collect at the top end of the filter where the water evaporates. I am pleased with the performance and longevity of this product