Sump advise

[Williams2020]

I'm new to reefing and using a sump for filtration I was advised by the previous owner of the sump that the way its set up is the best way to use it but I feel I'm not getting the most out of it the way it is as I'd like to add my nyos quantum 120 skimmer to it there is a large empty compartment in it not getting used any advise pls the tank is a 120ltr cube and 30ltre sump

 

[Mr. Mojo Rising]

a sump is not a filtration method, it is a place where the filtration machines are housed. Its completely up to you how you use your sump space, if you feel you will get better filtration from different equipment, then by all means go ahead and make the change. A sump is like a tool box, so you choose what equipment should be placed in the tool box