The tank came from me, and I answered the question for him, but I'll provide it here for anyone else with the same questions.
Tabris is correct: If the reg comes from Crossfire direct (and this only applies to Crossfire regs), there is a blue sticker for LP and a black sticker for HP outputs. Crossfire does sell a conversion kit Link
that as you can see, also comes with the blue sticker. In this case, I had not adjusted that tank and it was still set to HP.