i flower 8 plants in straight coco, the kind from the compressed bricks, in 6liter hempys with grorocks or hydroton in the bottom and coco on top, ...i feed KISS style with Jack's Pro Hydro which runs $50.00 for a 25lb bag of the base nutrient and another $50.00 for a 25lb bag of the calcium nitrate which is an increase in price since i bought mine almost 2 years ago, ...i still have enough for at least another 2 years but i gave some to my grobro because he liked the consistent results he saw me getting and after a few runs with the Jack's he now wants to order his own.
anyway, sorry to make a short story long but i should also mention that i run those 8 plants inside a 4 x 4 space around a single 600HPS in a kind of vert SCROG and i consistently pull 12 to 15 zipz per cycle, ...i haven't hit a pound yet but i'm getting closer, lol.
here's a couple of my early hempys when i was first learning the technique, ...these were fed nothing but
MaxiBloom and were grown under a 400CMH in 2liter hempy 'pots'.
...so i guess my vote would be coco hempy's, KISS style in a barebulb vert setup, easy peasy, lemon squeezy, lol.
peace, bozo