hey guys this is my 1st post anyway this is my 1st indoor grow a couple days ago i bought a 70 watt MH ballast fixture and bulb I already had a 100 watt HPS bulb for an S54 ballast btw the MH is a m98/e ballast for shits and giggles i put the hps in the fixture and it fired up i let it run for a couple minutes and it got pretty bright my bro told me the ballast he had made alot of noise and i saw people online saying that the digital ballast dont make noise so im wondering what i have because as far as i know that hps shouldnt have fired in there so i took that bulb back and got a 70 watt hps for a s62 ballast and this one fires too so my question is can i use both bulbs in this ballast/fixture