Step 2: Reservoir
2. In a straight line, on what will be the top of the reservoir, measure and mark the location of the holes for the planters. I used 4.5 inch centers.
3. Drill 1/2 inch holes for each planter. Take care to drill as straight as possible, for proper planter alignment later. Smooth away any burrs or they will cut into the Vinyl tubing later.
4. Bevel the ends of the pipe at approx. 45 degrees.
5. Apply a generous amount of glue to the bevels at each end of the pipe, around the full circumference, being careful not to increase the diameter of the pipe. Allow to cool fully.
6. Cut the top half off one of the bottles and insert over one end of the tube as far as it will go.
7. Cut the bottom off the other 2L bottle and insert the upper piece over the other end of the tube about 2 inches.
STEPS 8 AND 9 MUST BE DONE QUICKLY IN A VERY WELL VENTILATED AREA DUE TO TOXIC OFF-GASSING FROM HEATED PVC AND OTHER PLASTICS
8. Heat the clear plastic dome of the bottle from step 6 so that it shrinks tightly around the pipe, melts the glue and tightens over the end of the pipe. Be careful not to overheat the clear plastic or damage the threaded area with the heat AND heat the PVC pipe AS LITTLE AS POSSIBLE.
9. Heat the clear plastic from step 7 so that it tightens firmly around the pipe and then, using the pry bar and heat gun, shape the neck so that it faces up as in step 4 of Modular Hydroponics - Low Profile Reservoir.
10. Trim excess plastic away from tube using a utility knife.
Note - Both ends could be facing up, but it's only necessary for one. The other end is also the cap end of a bottle, rather than the bottom, because provides access into the tube.