ok so i picked up 2 150watt HPS lights and a "Y" split so i can run two. is it absolutely neccesary to purchase a ballast system to run them? i baught a metal lighting fixture thats rated for up to 400 watts, but i want to be 100% safe about this... im planning on testing them in a controlled environment before i put them into my attic but any advice would be gretaly appreciated since im scared of a fire hazard.