Upgrading refugiums, need advice


Reefing newb
I just got a different/bigger refugium that can fit a skimmer in it and I am wanting to get my supplies together to switch over to it. I got a trigger ruby36s refugium.
Trigger Systems - Sumps Detailed
Besides the filter socks, algae, and the skimmer what should I put in it? I have some small live rock pieces in my current refuge. Should I move them over to the new one and does it matter what section they are in? Do I need to keep the intake section kind of free except for the skimmer?
Also in the middle chamber do I need (or benefit from) having live sand or refugium mud.

The baffles between the refuge section and the return section there is a bubble trap about 2" wide that has a bottom and top grate. Is there a certain foam something that should go there or I read something about using new bath loofahs. Or maybe my small chunks of live rock rubble?
Remember every foam that you put in or socks, will need to be regullary cleaned and changed... Do put in some live rock (rubble) and algea, and mud or sand, it will just help the bacteria grow and will help to eat the waste...

Just check on youtube: type in sump/refugium or just sump. and learn from the eperiences.. It will be hard to decribe here by typing, it is easier to observe and learn visually :)
I wouldn't use sand or mud in the refugium. It will just take up valuable space. I'd go bare bottom with some macroalgae and live rock rubble.
Wouldn't the live rock rubble take up the same amount of space as sand or mud? Is the rubble better as a breeding ground for copepods?
Hmmm. From what I read I might not have enough flow through my refuge to keep ditritus from collecting on the rubble. I have a 635 Gph return pump. It has to pump up 4' and 2 90 degree bends, so I'm guessing it probably only flows 500ish.
I think I'm just going to go with nothing besides the algae. I can always add rubble later. Just going to try to keep it simple.