About 2 years ago I found Pod Racer's extensive blog. I was intrigued, but I had to read it 3 times, partly because these guys were pioneering it for mj, and were on a whirlwind learning curve, plus Pods esoteric rants.
As to be expected when pioneering, some of the assumptions were wrong, like the N dumping, which was probably nothing more than recirculating toxic runoff due to hormone changes during bud development.
Pod Racer called it "TAG", I call it High Pressure Aeroponics (HPA) and there is at least one significant variation. I am a personal use grower,so the system you see pictured here is of 2 totes (eaach tote can hold 2-3 AF plants. The pump can probably handle 4 totes. For largeer grows, consider installing an Accumulator.
Although you could grow trees with HPA (55 G drums) , it's particulary suited to SOG. Why? Root systems are as big as the plant. If you have a 5-6 ft plant you need a two foot cushion all around to mist the entire root mass. Also you need sufficient room below to keep the drain clear.
Relative Humidity RH inside the root chamber is improtant. Too much and you will soon get gnats, mold, algae, fungus...
If RIU puts up a HPA forum, I will start a journal.
1. The system in place. Note inline filter (200 mesh screen) between rez and pump
2. PVC couplers come in a variety of sizes. The one on the far left has shortest thread and largest opening. Makes it easier for nutes to get up in there. I almost lost 5 young plants using the others.
3.PVC couplers with neoprene puck. Note the ledge inside will prevent the plant from falling through once it gets heavy- and it will!
Roots tend to develop before you see much top growth
This was taken a week ago (9'). This plant was on death's door. I credit HPA with bringing it back. It is now over 12".
You won't find these roots in any other aero/hydro system, and they are
not the best. When the root chamber is totlly dialed in, all those hair like roots will fill with fuzz that are called root hairs. The fuzz significantly increases the surface area, allowing for more nutes to be absorbed at each feeding.