I one in the tank with and extra one so I just rotate them and throw the sock in the washer with hot water and cap full of bleach works real well, I have to change mine about every 4 days. I also have a thin one, dont know how many microns it is but it is like one of those bags you use to put charcoal in and if I am going to be gone for longer than 4 days I put that one on because it does not clog up but still catches debris