Hi! Welcome to the forum!
I would put them in order of how the water hits them, bioballs getting the dirtiest water or the first water that enters the filter compartment, followed by carbon and then the bio media should be getting the cleanest water as in the last stage of waterflow before going back in the tank.
What type of setup do you have by the way?
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.