What is this grow method called?

I usually use my 3 Aeroflos' for production but this was something I was screwing around with. Just a black tray, 4" cube sitting on about a 1/4 inch of hydroton, then more hydroton packed around it. I just watered and nuted the hydroton, no draining. The plant is 35" tall and that main cola is about 16" long. I find it interesting because it shows me that root mass and pot size are not that important. (there's no pot and hardly any exposed root) I know someone has used this simple method before. What is it called? Plant is 92 days in flower and I'll probably chop in a couple of days. Cloudy with some amber.