I am using two 400 watt hps lamps which i have been told by a reputable company is the perfect wattage for the space and amount of plants. It is a very professional and quality set-up. A hydro-pod system so they are not spread needlessly around taking up unneccessary space. 2000 watts for 20 plants seems slightly excessive, do ur plants droop as the daylight hours wear on and then pick up when the lights are off? May be stressing the plants a bit. Although 117 grams sounds pretty good man. Keep it up and cheers for the reply.