The WaterFarm 8-pack is eight WaterFarm module units connected to one General Hydroponics Controller: and integrated 13 gallon reservoir and an 8 gallon controller unit. The Controller will keep each unit topped off with the correct level of nutrient for low maintenance. The kit is powered by GH�s Dual Diaphragm Air Pump, and includes all the necessary hardware , supplies and General Hydroponics Flora Series nutrients. The grower can arrange the WaterFarm units in a design that is suitable for any environment. Pack them tight or space them out for your growing situation. The WaterFarm 8-pack is the system for big growers. This system does not include Hydroton.