That's interesting about the VG doing that. Coughing stuff up means your lungs are trying to get rid of what's there doesn't it? I guess we're lucky because Mike and I have had just the opposite. We're not coughing up anything since we started vaping. We've never vaped just VG or PG though - usually 60/30 or 80/20 - now that we're doing DIY it's 50/50 for simplicity. Patkin, have you tried changing your ratio?