I should be getting my filter in a couple of weeks but my gas is in the lounge room and the filtering and kegging will take place in the garage brauhaus. If I take the empty keg into the lounge then flush the keg and take it back to the garage will the CO2 be heavy enough to 'pool' in the keg so when it's full there will be little or no oxygen in the headspace? Up to now I have put 90g of sugaz into the keg as if it's a big bottle and after a week or so burped it thoroughly before connecting it to the lines in the kegerator so presumably would have flushed 99.9999 of any oxygen.