Here is a simple video explaining the design and build of the Deep Water Culture (DWC) system. These two modules will replace the ebb and flow system as the primary growing vehicle for lettuce. In a DWC system, the roots lay in a highly oxygenated nutrient solution while drawing dry air from the top area of the pot. It is critical for the solution to maintain aeration or the roots will drown.
I chose a DWC and this particular design for a couple reasons. 1) A DWC is very simple and requires minimal parts (air stone, tubing, air pump). 2) This design will hold over 5 gallons of nutrient solution providing a stable nutrient base. 3) This design allows for easy replacement of nutrient solution by simply setting the lid / pots / plants aside and dumping and refilling the reservoir.
I expect the same rates of growth as I have experienced with the ebb and flow system.