At least the option to have some mechanical/chemical filtering capability. Do you have, I am guessing yes, the flow coming down from the display split so that it goes into the fuge side and some into the skimmer side? Is there a place there, on either side, that you could stick some filter floss to remove particles from the water and or some bags of activated carbon, Chemi Pure Elite, Purigen to help to remove unwanted toxins/chemicals? If not could you fabricate a tray out of some eggcrate that could hold these types of things that would fit under one of the pipes/hoses coming from your display?
A number of folks will run tanks and be successful at it without any form of mechanical filtration however IMO it is nice to have the additional protection that floss, carbon etc offer to keep the water clean and clear. Just some thoughts for you.