Please help me set up my wet/dry and skimmer

I have a gulf stream wet/dry filter that I'm not sure how to put back together.

So I have the hose coming down from the top of the tank water goes down through the bio balls.... runs pass the media filters and to the other side of the sump and then pump back up with a rio 2500 to the tank right? But I have another hose that's open molded to the sump itself on the side.what hose goes through there?

I'll take some pix of everything if needed .

I figured out the gulf stream it required an external pump but decided that a 10g sump is too small for the 40 so I used my Del Rey 20g(i think maybe 25) gallon sump for the 40 and buy a new w/d for the 55 later. . I just got back from my LFS and bought a Jebo Lifetech 5400 to replace the current Rio 2500 and put the Rio to the Protein skimmer which I'll post pics ASAP... Guess I won't need the skimmer yet do I? It's in the cycling stage at the moment I don't plan to put any fish or anything living in there for a few weeks so I just put regular tab water in. (no salt yet) waiting for all the gunk and murky stuff that came out of the live sand to settle down.

**** you serious? Should have put salt in there in the first place eh? So what do I do now? I mean the live sand are in a bag to start with, what's so live about it in the first place?