I'm not a CO2 user, but the changes in pH when you add CO2 are to do with the change in the CO2 ~ HCO3- equilibrium, and aren't the same as changes in water chemistry, there is an explanation here <"pH drop & high alkalinity">.Reason I ask is, I particularly like the Sulawesi shrimp. Heavily injected C02 tanks will have lower PH than they like. Just wondering if they could gradually be made to get used to lower PH than they like and adapt to this