Dan, so long as it works, doesn't matter what kind of wrench you have./w3tcompact/icons/laugh.gif I like the three legged wrench because it'll work when nothing else will, as with recessed filters. However, if the filter is out in the open where you have room to work, my ordinary 16" channel lock pliers will work, too; just takes longer because you usually only have room to turn it a little at a time, but I use a ratchet with the three legged wrench.
Bird