Abstract: Tray assemblies organized in a vertical stack with a grow light positioned above each. Plant nutrient solution flows into a feed reservoir positioned in a first end of the top assembly. When plant nutrient solution reaches the level of outlets positioned in a sidewall of the feed reservoir, it flows into longitudinal channels positioned on the tray assembly. A collection reservoir at a second end of the tray assembly collects excess solution from the channels. A lip positioned between the channels and the collection reservoir retains some of the solution in the channels so it is available to plants held by the tray assembly. Excess solution flows from the collection reservoir of the top tray assembly to a feed reservoir serving the next tray assembly in the stack. The pattern is repeated while alternating the orientation of each tray assembly such that solution is provided to each tray assembly.