Okay, so here is how it is: I have an array of 540w CFL bulbs which produce ~22,000 lumens. I want to buy a better bulb with a ballast for two reasons: 1.) My plants aren't growing very fast under the CFLs. 2.) I need something for flowering, which the CFLs won't do. So, I have to get HPS, which means getting a ballast. Question is - which ballast? Digital is better but I can't find it near me so that's another week of subpar crops while it arrives. But I also need Metal Halide if it's going to replace the CFLs for vegetation, right? What about Dual-Spectrum bulbs? They work on analog ballasts and I can get one right away. But will DS be as good as MH for vegetation? Really appreciate the input!