The grow tubes are made from 36 inch long pieces of 3 inch PVC sewer pipe. Each tube has 6 holes that are 1 and 7/8 inches in diameter to accomodate a 2 inch mesh pot. The holes are spaced 6 inches on center from each other and spaced 3 inches on center from the ends of the tubes.
On one end of the tube is a plain 3 inch PVC end cap. The end cap is not glued in place but still fits snugly on the end of the pipe and makes a watertight seal. The cap can be removed from time to time so a brush or similar item can be used to scrub out plant debris.
On the other end of the tube is another end cap with holes drilled for the water supply and drain lines. The fitting for the drain line is a CPVC 1/2 inch male threaded adapter. The threaded end of the adapter is inserted into the end cap and secured on the inside first with a rubber O-ring and then with a 1/2 inch PVC lock nut. The supply line connector is a 1/4 inch O.D. tubing bulkhead union also secured to the end cap with a rubber O-ring and lock nut.