My 'room'(corner of the room,2 real walls,2 just black/white foil) is 1.60x1.70x2.50cm,to be fair the 600watt is actually boosted to about 630watt(dimmable/boostable Lumatek digital ballast).
No intensive techniques,just good soil,organic nutes,mostly biological pestcontrol(nematodes for fungus...