So this professor Kratky over in the paradise state of Hawaii developed a passive hydroponic set-up that allows the roots of the plants to follow their nutrient solution down as they soak it up. There is no need for air pumps, tubing, or circulation (Yay!!). The roots adapt to the situation differentiating into air roots (near top) and food/water roots (below). You try to give the plants a big enough solution reservoir to last the growing season. But if that isn't possible, just refill it, but not all the way, so the air roots don't drown.
I started a lettuce mix from seed in coco coir pellets. After a week and a half or two weeks, I transplanted them to their permanent home - a 10 gallon tote with net pots inserted into 2-inch drilled holes. The tote was filled with 7 gallons of nutrient solution using General Hydroponics Maxigrow formula. 7 gallons of water brought the nutrient solution high enough to just go over the bottom of the net cup. It turned out to be more than enough solution to support my plants for their 8 week growing cycle that included 4 weekly harvests starting at week 5 from seed. The tote was placed under my JumpStart grow light system that had 4 T5 bulbs in it. The lights were on 12 hours a day.
Below are pictures documenting the grow cycle.
Here is the wonderful weekly Asian-inspired salad I enjoyed.