From the symptoms you describe, it's more likely your tank is starting off dry/badly wicked. The cough is your body's reaction to aldehydes due to scorching of the wicking. Not exactly healthy. Try shaking your clearo before you begin vaping for the day and after making sure it's well filled. Failing that, increase the PG to VG ratio of your juice mix. VG is usually responsible for insufficient wicking between puffs resulting in too many dry hits (and coughing). For my Nautilus, I've found 60-40 PG/VG to give the ideal vape, with copious vapor, good taste and the absolute minimum of scorching. YMMV.