Research has indicated that the addition of oxygen at 12 hours into your lag phase increases fermentation speed by 33 percent...
Most brewing texts cite the ideal level of oxygen in wort prior to fermentation at around 8 ppm or 8 mg/L.
Running the gas flow at 0.2 liters per minute for 30 seconds will introduce about 0.1 liters to provide that volume of required oxygen.
My question for those that use the 12hr approach is should the rate & duration of the addition be the same or different to the initial oxygenation.
Thanks for your help