Don't bother with the charts and that KH, CO2, ph relationship. It really isn't helpful at all for what we do, as there are other factors that throw it off. Instead, most of us just go with the amount of ph drop between the off gassed tank water and peak co2 output.
Take a cup of water from your tank and let it sit for 24-48 hours and then test the ph. In that amount of time all of the co2 will have offgassed from the water. From there a peak 1.0 drop in ph puts you right around 30 ppm. You can push it farther if you want more....most try for between 1.2 -1.5......depending on your livestock. You have to up it slowly though and watch to make sure your fish aren't gasping at the top. If they are, you've gone too far. Back it off a little and leave it there. Test ph on a regular basis as it usually changes a little over time and could leave you with more or less co2.
Beautiful tank shots btw! love your journal!. I really wish this community would stop quoting absolute pH drop ranges. Your max CO2 concentration(can be less) can be loosely estimated measuring the change in pH from degassed Tap versus co2 injected tank water. A rough conversion of pH to CO2 can be estimated based on the original off gassed kH of the water and converting the pH change to a CO2 concentration. That is what Tom Barr's (ph, kh, co2) chart is all about.
An absolute pH drop is meaningless unless we know what the kH of the water was to begin with. So saying shoot for a 1ph or 2ph drop and ignoring the charts is not very helpful.
1) Off gas tap water in open container for 24 hours and then measure its pH.
2) Measure your in tank pH and take the difference
3) Measure your kH of off gassed Tap water using the API test kit or other.
4) Lookup your CO2 levels on the (kh, pH , CO2) tables (google this chart from Tom Barr).
This method will give you a reasonable estimate of your max CO2 levels in your tank. The concentration of CO2 may be a little lower as there could be other sources of hardness in your source water that is not Carbonates but we basically assume those are not high.