i just ordered a 400 w hps from htg tonight, and it comes with a 400 w hps bulb that puts out 50,000 lumens. The purchase kinda put me in the whole as far as money is concerned, so my question is, am I able to successfully vegetate and flower in just the hps bulb? Or do I need to spring for a mh conversion bulb (not really a possibility as of now)?