Nice photos, Hoppy. Let us know how it works out.
Actually, it looks a lot like the first internal reactor I build for my 29g with DIY CO2. I did add an air stone to the bottom of my CO2 line to help break up the bubbles, and I certainly didn't have the feedback look and burp hole. Might have to break it out and modify it and give it a spin. Oh, and I used an old gravel vac for my 'tube' part.
46g bf, XP3 w/ vertical spray bar, CO2 w/ SMS122 & diffuser,100% Flourite, 96w+55w cf AHS, AGA Member