This shot shows the main tank (bottom right), the sump (lower left), and the two main grow beds. The water is pumped from the sump to the grow beds which empty into the main tank via auto-siphons. The tank then drains back into the sump. The IBC container cost me 20 dollars but did not come with the steel cage. I built a wooden frame and lined the tank with 2 inch Styrofoam insulation (we have cold winters in Idaho.) The Blue barrels were 15 dollars a piece and had been used for food flavoring in ice cream production. On the right side of the photo you can see the return pipe from the vertical wall unit.