Here is the reactor I just finished, using pvc all around instead of the vinyl tubing. I have a mag 5 pump on it (probably overkill but that's what I had). There is a threaded Tee for each of the I/O connections, the one above the pump is for the water to come in from the tank, I'll get that from my sump return. The one just before the pump is for the CO2, and the one just before theCO2 input is for effulent out.
Now I just have to wait patiently for the CO2 tank and regulator to arrive. I'm very interested to see what the bubble count you guys finally arrive at so I have a good starting point. I'll only be feeding a 45 gal tank (70 gal total volume) so I should have no trouble keeping up.