Sump question
 

I have noticed that the usual sequence of peoples sumps is intake compartment with skimmer/ refugium/ then return. Why is this? Wouldnt the refugium benefit more if the skimmer was placed after the refugium?

I have had many sump designs, and like my current setup best.

1. Display tank flow enters skimmer compartment at end (semi-recirculating zone), and overflows to center chamber filled with LR & eggcrate (Berlin/benthic zone)
2. With a ball valve, display tank flow is also metered to a refugium section at opposite end, which has it's own sand or mud bed. The water movement through this section is slow and doubles as a pretty good pod factory.
3. The center chamber is where water scrubbing (Rowa, etc.), and water monitoring/adjusting is done and is also where the return pump draws water.

I think the biggest hurdle with a center-draw sump is micro bubbles, but solved if there is a sufficient pile of LR (or like) over the return pump inlet. This can be done with a minimum of baffles which can be a waste of precious space if you ask me...

The advantage of the usual setup is any pods in the refugium can return to the main tank without going through the skimmer