Plants grown in RDWC setups have easier access to oxygen and nutrients, which means they spend less energy searching for nutrients and developing roots. As a result, plants will reward you with fast vegetative growth and excellent yield. Root Box Hydroponics RDWC Lower Feed Grow System is (4) Large 12 Gallon Low Profile Grow Modules connected to a 5 Gallon Controller Unit. This system uses a 950GPH (10) Air Pump powering (10) 2" Round Air Stones oxygenating the roots. A 800GPH Waterfall Pump is used to recirculate nutrients. The Waterfall Pump sends the nutrients in the lower 1" tubing up through the 3/4" tubing to the Waterfall fitting in the Controller Unit recirculating the nutrients. Root Box Hydroponics Grow 4 Lower Feed RDWC System Includes- (4) 12 Gallon Grow Modules with Screen Fittings to keep the Waterfall pump clean. (1) 5 Gallon Controller Unit with Drain Tube, Holding Clip, Water Level Bands (2) 3/4" Chiller Fittings w/ Down Tubes (1) Float Valve w/ Green Inlet Fitting (1) 3/4" Waterfall Fitting in Controller Unit (4) 10" Net Pot Lid Baskets (1) 950GPH Commercial Air Pump & Outlet Air Divider (1) 800GPH Waterfall Pump, 1" & 3/4" Fittings (10) 2" Round Air Stones (10) Airline Sets with Submersed Section Dividing Connectors (18) Steel Hose Clamps (1) 4ft System Drain Hose with 3/4" Barbed Connector and Clamp All Pump Tubing, Bulkheads, Module Fittings & Hardware included for a quick easy install. System fits inside a 5' W x 6' L Grow Space. Shipped with a private brown box.