Hello fellow smokers, I purchased a switchable ballast for my 400 watt lighting system. I used a metal halide bulb for vegging and am now ready to switch over to the flowering stage. My question is this: What do I have to change on my ballast settings in order to do this? The ballast has two settings, one for metal halide and one for high pressur sodium, so obviously I have to change this, but do I also have to switch the voltage? I currently have the output set at 120 volts. There is also a 240 volt outlet, so do I have to toggle the switch to this for high pressure sodium also? I'd appreciate any imput, thanks in advance.