For 10 LPM LiveO2-Adaptive Contrast and Extreme O2, the fill time is approximately 1 hour when the system is set for fill.
When you fill the system be sure the slide control is set to -O2. Note the position of the slide gate, which closes off the oxygen port. During fill this position prevents oxygen from escaping from the fill.
Also, the oxygen flow should be set to the maximum flow of the concentrator. The ball float indicator should be positioned at, or slightly above the maximum fill level.
*It is important not to overdrive your air separator. For specific instructions on how to properly set your oxygen flow rate meter, follow this link: http://whnlive.com/support/air-separator-warning-light-and-alarm-sounding/