the answer is no, you gotta have a ballast to power these lights, both mh and hps are totally unlike standard house light, they both need a 'boost' to get started and only the ballast provides that. sell your 2 mh bulbs and buy a 400 watt mh with switchable ballast(this means the ballast will work both mh and hps). use the mh for veg and hps for flower, u could also sell the extra hps bulb if ur shorta cash but i'd keep it coz its alway handy to have a spare.