A net cup holder for use with a hydroponic vertical tower system, the net cup holder including a support portion, wherein the support portion is sized and configured to angularly retain a net cup therein, and a mounting flange at least partially surrounding the support portion, wherein the mounting flange is configured to provide one or more mounting points for the net cup holder to be mounted to an exterior surface of a vertical tower. The net cup holder further comprises a hole interface portion, wherein the hole interface portion is sized and configured to be inset within a hole formed within the vertical tower such that an interior face of the hole interface portion is flush with an interior surface of the vertical tower.