Thanks, pandacory - I'll see what I can do about the refugium plumbing.
Good point about the weir/water level, but the weir today is only 1/4" - I expect the same on the new system (plumbing restrictions will make it worse, but it's half the width, so should end up the same).
In my power-down tests, the 30G sees a rise of ~1-2", whatever that volume works out to. 50G will probably be similar with my layout. There should be about 2-3x that amount available. I will, however, go back and actually calculate this - again, valid point.
Well, last night I filled the spare tank for water testing. Despite my thoughts that the top plastic ring did nothing, the middle bowed a fair bit, so I threw a clamp on it with very light pressure, just in case. Also tossed a little pump in there to keep water moving.
With the tank purchase came a few bags of some sort of biomedia...I went through this article ( http://www.monsterfishkeepers.com/fo...o-Filter-Media
) but it did not mention the type I have at home. This leads me to believe they are not media at all, but in fact just the stuff used for hydroponic gardening.
I did see those used here, however: Bogopolis journal
RobMc's sump has them in the drain area...I figure if nothing else I can add them in...better than just water taking up space. Further to this, I'll be revisiting the sump design, adding another baffle section, and ensuring the wet/dry area is a true wet/dry.
In other news, I made the mistake of researching fluidized bed filters (FBF). Fluidized bed filter?
This has led me to wonder if even a small FBF could be used as a 'okay, stock levels are a bit ridiculous, release the FBF'. Not that I expect to require one...but very interesting nonetheless. Another link here: http://www.cichlid-forum.com/articles/diy_fbf.php
The Youtube guy, uraujoey (sp?), did a how-to on FBF a year ago or so, and DANG it looked so darn cool. He didn't do sand, I think K1, so slightly different principle...but it looked so awesome. Anyways...no budget right now, but good to know it's a functional piece of filtration tech.