Filter socks are useful for trapping tiny particulate matter, but they can be quite the pain in the butt. For starters, a new filter sock will cause your skimmer to go crazy for a brief time. It will skim very wet and overflow the collection cup. On top of that, the sock clogs after only a couple of days, forcing you to swap it out for a new one very frequently. On the flip side, the socks can be cleaned very easily, allowing them to be used over and over again.