OK, I finally got a chance to take some pics. My air pump which is Active Aqua Commercial 12 112 watts 110 lpm is hooked to column in res. Also located above water to avoid any water making it back to the pump. The valve is installed in the very first line from the air column and blue tubing (prob. 1/4 turn closed to restrict some flow. Then it connects to fitting in grommet and goes into room to first waterfarm, then all of them connect and last waterfarm is routed back to other line in res. One blue and one black. All waterfarms have an air tube with drip ring and there are two small round air stones in the res.