Next up in between each of the tubes mount one of the pumps to the top of the frame. If you want you could do it to the bottom instead... but I don’t really care. This is how I did it...

Here is a quick shot of all the pumps in place. Note that the protective caps are still on the pumps. Keep them there until your ready to put something in them.

At the right end of the reactors frame we hot glued one of our valves to the frame. we modified it slightly with a plug so it no longer passed through but required the valve to be open.

Here is a diagram of the air hoses. Note that you can choose to recycle a portion of the air by adjusting the outlet valve and the recirculation valve on the right

So here we start getting the plumbing hooked up. We have the air from the last tube in the system plugging into the common line on the valve. The knob on the left is the recirculation valve and the one on the right is the exit valve that just vents to the atmosphere.

Every other tube we will connect to the input on a pump to boost the air pressure along the array of tubes. The seal from the second tubes outlet to the next pumps input should be air tight as there is no booster pump between every other tube and you want the pressure to do the work for us.

Here is the input valve. The valve on the right is the recirculation back pressure valve. The knob on the left is the input line to the first pump. The stem on the right is the input to the system from your CO2 reeking house and or apartment, or factory, or forge, or maybe you smoke a whole lot... or like lots of soda pop... I dono, some CO2 source.

Here is a shot of the back of the rack. The line running from left to right is the recirculation line. You can see here the output lines being hooked up now. A few dabs of hot glue hold the lines down really well and hold very well on the pine.