Sump design:
I researched a lot of different sump designs and settled on something I think is going to work really well. Stemming from my initial post, the sump needs to:
1) Get rid of microbubbles.
2) Be large enough to easily fit in the main equipment (skimmer, ATS)
3) Have the return section be large enough that I can do 10% water changes
So this is the design:
Since the tank is a peninsula design and the overflow and returns are on the same side, I went with a U-turn sump design where the water will come in on one side, go around the sump and come back out the same side.
It starts in a filter sock section (which will probably be empty most of the time but gives me the option of running socks if I want to). Then it goes into the large and open equipment section. Goes over a couple baffles into a refugium/frag/whatever section, then over a final set of baffles into the final section which is where the return pump goes and serves as the WC reservoir.
The dimensions are 6' x 28" wide x 20" high. It should *just* be able to squeeze into the stand which will have a 29" opening on each end.
The operating depth of water will be 14" and in normal conditions the sump will hold ~120 gallons. With an extra 6" of space it will easily be able to handle another 50 gallons of overflow which is way more than the DT would ever drain in a power outage.
The equipment section will be roughly 43" x 15" which is more than large enough for the skimmer, ATS and some extra space for other equipment.
The return section/WC reservoir will be somewhere around 35 gallons, which means I'll be able to do 30 gallon WCs without running out of room, which will be about 10% of the water volume.