update, pH started to crash my KH is down to 4 and ph is down to i think 6.8-7.0 that's down from 7.6 so i am looking at about 19ppm of co2, a little concerned about even lower pH 2 night and too high co2 i plugged in my air stone to be on opposite of my lighting, i have a digital power strip with timer and it has on & off plugs. when 1 set is on the other is off, and when 1st set turns off the 2nd set turns on, . i m gonna have to watch it but i think that the 2 1.4 liter bottles will be great! i also realized i dbled up on ferts when i made last mix, i got distracted when taking pics.