As minimalist setup, your filter consists of:
Depending of your water parameters and quality, you may have to clean times to times your tubing.
If there is an issue with the paper, some waste can be accumulated in the SUMP. It is then always a good idea to optimize water changer to clean it. My method currently, is to disconnect secondary / emergency intake from roll paper box, and let the water from the tank directly circulating in the SUMP. The strong stream will wash out all placers before to be pumped-out e.g. to toilets.