Mattheyn;

You might consider checking out my drilled 10 gal. I'm going to sell it when I move; maybe I could let it go sooner. Trying to keep some sort of external overflow going with the limited flow in a 10 gal sounds like a nightmare to me, although I can't really picture what you're trying to do.

School really slows down for me this week; classes end, and i only have one day of exams to give next week. Why don't you come over at some point to check out my set-up? It'll give you good ideas, I think, even if you're not interested in buying. It is tough to drill a 10 gal; I just got lucky, or rather, Mike at Aquarium Sales and Service got lucky. But, it's been trouble free for almost 2 years, since I set it up. The overflow area is tiny, but I push a solid 200 gph through it.

Another thing, I'd be pretty skeptical about the 2 1/2 capacity refugium, unless you're really going to trickle water through it. Mine is 5 1/2 gallons, and if I could have figured out a way to get another 10 on that part of the stand, I would have used it. The thing is, if you have a decent flow, it will be tough to keep sand and crap out of the pump in such a small space; water moves a lot faster through a smaller space.

I'm not trying to diss your idea, only share my experience with a similar set up.

Matt