I use one sponge, a piece of filter pad from my old filter, a media bag with carbon and the biomax (in that order bottom to top). I know many here skip the carbon. With my well water, I prefer to use it, but buy it in bulk and put it in bags I bought at Dr Foster and Smith (an official vendor here). As recommended by others when I asked, I only ever rinse the media in tank water, except for the carbon which I replace monthly. I love my AquaClear.