For the more adventurous gardener, General Hydroponics offers the PowerGrower 8-Pack Kit that includes a hydroponics system controller. 

This top feed / drip hydroponics system has hexagonal (6-sided) shaped growing containers - Each measuring 15" across and 15" tall, making them ideal for a larger sized plants, such as blueberry bushes or tomatoes.

The growing containers placed together create a high performance hydroponics growing area measuring only 4 feet across. This efficient use of space resembles a high-density honeycomb. As plants mature you are able to move them apart to give them growing room.

The PowerGrower 8-Pack Kit is built from high-impact plastic that will give you years of pleasure. Comes with everything you need to start your hydroponics garden:

3-gallon Growing Chamber - 8
Individual Reservoir - 8
Split Tees - 8
Drip Rings - 8
Clear Airline - 8
Pumping Columns with Support Tubes - 8
Reservoir and Controller - 2
Reservoir and Controller Lid - 2
Hatch Cover - 2
Blue Tubing - 20 ft.
Reservoir and Controller Connecting Hose
Float Valve with pipe thread compound
Controller Drain Level Tube
Circulating Pump Column with Collar
Circulating Pump Connector with Split Tee
Individual Drain Level Tube with 1” grommet reducer
Single Output Air Pump
Dual Diaphragm Air Pump
Illustrated instructions

The unique "Split Tee" connector design ensures a uniform delivery of nutrient solution to each and every grow chamber pot!

More info (PDF format)