Skimmer Question

[ewelch]

I just bought a CPR bak pak HOB skimmer. I bought it used and am unsure how to set it up. I checked the site for CPR and they have skimmers like mine but there seems to be an extra acrylic box that I dont know what to do with. Also this may seem like a stupid question but the Rio pump that came with it is ok to put in the tank. I mean waterproof and all.

Oh and the filter media that goes in it. Is it absolutely necessary? I will get it if I have to. I am also running a pengiun filter without the biowheel in this tank.

Thanks for your help.

[ewelch]

I just answered a few of my own questions with a little more research. I believe I figured out what the extra acrylic boxes are. A preskimmer and a bubble eliminator.
Are they worth using? and I still am not sure about that biofilter or filter media.