I am pretty excited. I ran across a good deal on a 125 gallon reef ready tank, cabinet, wet/dry sump, sand, rock and even an Asfur Angelfish. My dilemma, is I don't want to use bio balls. I would like to get rid of them but I do like the idea of a refugium for macro algae and copepod reproduction. Also I need to use this sump. Although it was a very good deal, it tapped my extra funds for a while. The sump is an "L" shape if you lay the L on its back. The short leg sticking up is where the water flows in from the tank. It has a drawer for floss media of some sort, a compartment (doesn't look like it opens) for the bio balls, then the water drains through a small compartment with some type of hard sponge filter into a larger compartment which I assume is where I put my skimmer and heater before it returns to the tank. Any suggestions on revamping this sump to use with no bio balls?