Sumps itself dont filter anything, its what you can put in the sump that you cant (more specifically wouldnt) put in the main tank that can act as filters.
If your gonna do a canister filter, dont bother with live rock rubble, just do a sponge and depending on how dirty it gets, id say clean it every 3-6 days. No need for bio-material though unless you dont have live rock in your main tank.