The WaterFarm? 8-pack is eight WaterFarm module units connected to one 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 Flora Series? nutrients. The grower can arrange the WaterFarm? units in a design that is suitable for any environment. This system does not include clay pebbles.