OK, so I have my new gas fireplace installed and a brand new 420# propane tank ready to be connected. The tank is prepurged, vacuum inside (or should I say vacuum "not" inside?). Anyway, the tag on the tank says to initially fill through the service valve, adding methanol. Should I expect the gas company (I didn't buy the tank from them) to do this? Any reason I couldn't put some propane in from another tank (like a 20# portable tank), first adding the appropriate amount of methanol into the connection fitting?