What is the point of measuring CO2 with a DIY setup? Even if it's not where you think it should be, you have no way to adjust it. DIY is just plug and play, and hope.I have a twently gallon tank, and may be running a nutrafin co2 kit with DIY mix. My question is, how can I determine my CO2 level? I hear the Ph and Kh cross reference chart is unreliable.