hi all. im moving up to hps from flourescents and would like some feedback on which wattage to get. im thinking of 400 or 600. my space is 3 feet wide 4 feet long and 7 feet high. i only plan on having 4 females at any one time. would 400 watts cover the area with a rising sun reflector
Go by the number of plants, 400 is very nice for 4 plants. Consider getting some boards or something covered with mylar or painted bright flat white to pen the light coverage area in a bit, perhaps 3x2. If, however, you think you would want to do more plants at once in the future get a 600, and still pen it in for 4 plants.
600w is the most lumens per dollar over any wattage hid. if heat/vent won't be a problem, go with a 600. any doubts, go for a 400w. 400 is great for 4 plants though.