If i set up a 4 x 4 grow it would be sea of green using clones with 6 to 8 nodes & zero side branching , i'd do 25 plants in a 4 x 4 flood table & end up harvesting between 2 to 3.5 ounces per plant for a grand total yield of around 50 ounces .
Numbers quoted are half my normal harvest weights using my 4 ft x 8 ft tables where i use 3 large hooded 600 watt hps for total canopy coverage with canopy touching the glass for excellent deep penetration .
Nothing beats SOG when space is small as you are using , you should pull a minimum of 3 lbs from 4 x 4 space with sog .