This wet/dry was part of the deal I made for my set up. So how do I convert it? Of course the bioballs must go (unless there's been some "new" breakthrough in the past year that bioballs are in agan

) I thought of leaving the "sifter" at the top level as I don't want water splashing over/down the baffle. I really want to get some use out of this since I'm hoping to use the integrated skimmer for awhile until my bioload ramps up.
Which brings up questions about the skimmer. Without seeming like a dummy, I'm from the old school and have never used a skimmer before. I understand the concept and how it works but have a question about how this one would work. I know the airline going from the pump into the cylinder is for foaming action, but what is the purpose of the extra black tubing coming from the pump which ends inside the first chamber? (see arrow)
Also there's an "outlet" (looks like the airvalve on a normal air pump) on the other side of the upper chamber of the skimmer. Is it for a collection cup or something and how do I set it up? Sorry it's out of the pic...I'll get one of it if necessary.
Here's a pic of how the previous owner had it set up. I was planning on capping off the upper return to the rubbermaid for now until I need/can afford another skimmer. Although it would be nice if I can somehow use it for either a settling tank or extra security from overflowing.
Any constructive tips would be greatly appreciated! The tank is a 135...what size external pump do I need for a good flow? I am going to pipe the dual returns at the bottom into spraybars into the main tank. And probably a maxijet or 2 for added circulation if needed. (although I checked out the
Tunze Stream and may get one of those come bonus time in September).