Harm reduction is important. Normal sodas are pretty acidic - coke has a pH of around 2.5 Soda water has a pH of 5-6. Your saliva has a pH of around 6-7. Wa

Harm reduction is important. Normal sodas are pretty acidic - coke has a pH of around 2.5 Soda water has a pH of 5-6. Your saliva has a pH of around 6-7. Water, of course, is at 7. Remember we're dealing a log scale here, and that going from 2.5 to 5.5 isn't a 2x improvement - it's closer to a 1000x reduction in the amount of acid. If replacing soda with soda water is what gets them to stick to it, that's what they should do.