Hey all, thanks for any input. I am moving my set up- 100gal mixed reef/ Aqua C ev120 skimmer,and at present 23"x13"x16" wet/dry. I am going to be upgrading to a 36"x15"x16" sump/fuge .My questions are ...swap out the sumps but keep bio balls in first chamber with skimmer,helping ease the stress on biofilter? Then setup refugium and slowly remove bio balls? Or just do it all at once? As I'm adding volume to the system, not sure if a new skimmer might be good idea? And lastly(for now!) what to place in refugium- substrate,macro,rock from DT? Thanks again!