Ok, here's the situation. My parents went away on a week's vacation, and... they left the keys to the brand new porsche... oh wait... wrong forum and decade. Ha.
Right. So I'm planning out a 90G sump/refugium for a 180G in-wall tank. What I hope to get out of the refugium is nutrient export, pH stabilization, and chopped up bugs. I would also like to be able to remove 20G of water from the system without having to turn off the MAG 12.
So what I came up with was the picture below. 8" for the skimmer, three baffles 2" apart with the third one 2" at the top and 3" at the bottom so that the water flows down the baffle instead of falling into the return area and creating more bubbles. After the 6" return area containing the MAG 12 is another angled baffle holding back the refugium.
So the problem that I ran into is that the return area (if all the baffles are solid) maxes out at about 7.5x18x21 -- or about 12 gallons. I'd be able to remove 10 before the MAG starting pumping air. Not ideal. If I grow my return area (I'd have to double it) I'd have room. But i'd still be running it at 21" high which makes for a pretty full sump.
So I thought about it and figured if I drilled 4 1/4" holes in my refugium baffle, I could run the refugium/return area at about 18". Removing water from the return area would cause water to flow from the refugium to compensate. If I drilled the holes 6" up from the bottom I'd be able to remove quite a bit of water before running into problems with the MAG pump...
This seemed to be a viable solution for me. What do you all think?