1/4" Vinyl Tubing Vinyl Tubing may be installed above or below ground. The 1/4" vinyl tubing serves as the distribution line into which drippers or micro sprinklers are inserted. 1/4" vinyl tubing is used as the primary feeder line from the 1/2" mainline poly tubing to the plants. 1/4" vinyl tubing can also be used as the basis for a complete system for containers and patio plants.