Been vaping for 3 years and in the past 6 months I have developed a tickle with a cough when I vape. I don't cough every time and lung hits are not has bad as as inhale and absorb type hit. I read on one of the other treads about adding saline to the juice, but I don't know how much. I'm mostly doing 70/30 pg/vg liquid. I really don't want to go all vg if there is something else to do. Any suggestions. No I don't have a cold, allergies or sinus problems.