This is a plan that I'm putting together. I tried a grow once using the DWC system. When the plant were ready to go into the flowering stage, they started dying back. I didn't know why until I researched and found out that I had to keep the water on the roots cold. The roots were turning yellow and mushy. So I never tried again. I recently saw another post about water chillers and saw the cost. Then I saw different methods to build your own water chillers out of AC units, water coolers etc. I didn't see anything on refrigerators. Here my take on this problem. I went as far as I could with the design, now I need some professional input. Take a look as see if you can see what needs to be reworked before I start building it. It going in a 4X8 grow tent outside.