Pure Oxygen is used for oxygenating your wort for optimum yeast health. Use with either the Blichmann Oxygen Flow Regulator or the Blichmann Premium Inline Oxygenation Kit.
Is your tank past its Hydro test? View the example below to check.
Is your tank actually empty? The fill gauge on your regulator is not accurate if your tank/regulator is in the fridge. View the photo below for more info on how to weigh your tank.