I recently learned (after buying some, of course) that oxygen barrier tubing like Bevseal Ultra has about half of the resistance of the traditional vinyl tubing. So, for 3/16" tubing you'd need about 12-15 feet for an average CO2 level. I decided to swap it for EVA barrier, another double wall tubing with a barrier layer, because it comes in a 4mm ID which lets you use more traditional line lengths. Haven't got it up and running yet but so far I like the push to fit connectors. No more hose clamps!