I'm starting to figure this out. I have some 50/50 blends from a local shop but mostly 80/20 PG/VG from MBV. The 80/20 seems to make my throat sore if I puff on that all day so I'll have to try ordering some lower PG next time for my ADV. I have been feeling really thirsty & dehydrated lately, that is from the PG?? Crazy. I already don't drink enough water so that sucks.