Alrighty!

Thats the top view. I like the refugium idea because of all of the critters it would produce + the addition of nitrate removal with LR and Sand.
Since the top is a fish only tank the UV would be essential. You are making me rethink the whole process however. Maybe just a simple
trickle filter would be fine. Why do you think the bulkheads are in strange places. I put them in those locations so they would recirculate the devices they are attached to. So your saying put the UV in front of the skimmer?.....
Thanks again...
do you have any links or pics of your sump?