Product review (2 stars): does not wick
All of the filters with the same label "WF813 ReliOn Humidifier Wick Filter" are NOT the SAME product.  This product, by Completer Filtration Services Inc., does not have any stabilizing material to keep it from collapsing when wet.  It feels like coffee filter paper almost.  I had ordered a product from this same company back in December 2012 and it DID have some stabilizing material in it, so the filter did not collapse when wet.  Both filters, however, became what I call "calcified" after a week or so.  This made it useless, even though I used filtered water (I did not buy distilled, just water from our filter system--not soft water).  At first discovery, I "cleaned" the filter by soaking it in vinegar.  This did remove some of the calcification, but the filter still hardened up quickly after cleaning.
We have been using the collapsing filters by stringing them to a piece of embroidery plastic to hold them upright.  It's a temporary fix until we use all the filters.