For those of you who know her, Dr. Elaine Ingham is in my opinion THE leading source for information on the soil system. A simple search on YouTube with the key terms "Dr.Elaine Ingham roots of your profit" presents you with a lot of her seminars that have been taped. In her seminar roots of your profit she describes the common misconception that professional greens keepers (or whatever you call the guys who tend to the grass on golf courses) whom all said that the roots only go as deep as the grass is tall. Ingham showed that in just a short period of time, with proper biology and soil structure, that a short grass plant could have sever feet of root growth. Being that cannabis plants grow much taller than grass plants I'd obviously scrap the deep as it grows tall theory but I'd argue that if you have thriving biology and perfect soil structure one could benefit from upwards of 2' soil depth or more INSIDE! I have (well not me personally) constructed two 32' long X 4' wide X 2' deep raised beds using wood frames and spin bound poly (smart pot fabric) they are each 10 cubic yard of soil. Each light next round will have one plant Becuase they grew soooooo huge this round they fought for light and space. With only 16 lights that's 1.25 cubic yards or 252 gallons per light (4x4 area). I put teens into the room and vegetated for just over a month (issues with the cloner caused a delay) and while I planned for a canopy at 8' (6' tall plants) several strains stretches much last that in the beginning of flower. My Lemon OG plants that went untrained are 9' tall from the soil. They stand at just under 11' feet tall inside. Thank god it stopped stretching once it got to the light which was as high as it could go. So for those no till growers with tall ceiling and who like to grow large plants I'd like to know your thoughts on large volumes of soil indoors. Another side bonus was that my humidity stays at 65-75% except for when it waters. I vent dry air in during the night cycle to drop it but during lights on with the AC it's the perfect humidity without my humidifier. This also begs the question does the width of your con stoner matter? My beds 32' long so it's not a good measure of the limits of width but I see lots of great succes outdoors in 1,000 pots. Anways, I'd like to hear others thoughts on pushing the limits on soil depth.