Correlation does not mean causation... Just because your (and your friend's) alk went up, it may not have been a direct cause of the carbon dosing. ie If you have mainly LPS and the bacteria is out-competing them for a food source(maybe dissolved organics?), you don't have as much growth and not as much alk uptake. Alk would be noticed much sooner than Ca since it's in such a lower quantity. anyway, that's just BS conjecture, but this hobby is VERY interdependent and it's very very difficult to say (especially without an identifiable chemical rxn/process) that A caused B. I for one have not seen an alk increase directly from dosing vodka, but I test very often and adjust dosing dynamically, so I can't say that empirically.