Interesting....I take it by having it pre-mixed and ready to swap over, there will not be any issues of pressure?Once theres no more bubbles get rid of the mix, wash out the bottle and start over. Best thing to do is to have a 2nd 20oz bottle ready 2-3 days before.. so all you do is switch up and theres no drop of co2/pH.
once you open the cap off the bottle the pressure will drop (duhh lol) but since you already have a bottle thats been ready and producing co2, the turnaround will be much faster, minutes instead of 12-24hrs..Interesting....I take it by having it pre-mixed and ready to swap over, there will not be any issues of pressure?