I'm in the process of building a new sump. Space is very tight and I can't find a good spot for a filter sock in my first chamber. It's a basic "skimmer > fuge > return design. I could add a sponge prefilter to my return pump that would help with water polishing, but how important is it to have all the big stuff filtered out before the fuge? My fuge will be nothing but large LR rubble. Am I just asking for a ton of buildup this way?