I put a new carto in my tank with my new Papa Smurf juice today. After priming the carto and filling the tank I took my first hit or two. Initially I got three air bubbles come out of one of the two punched holes in the carto. After that I have not gotten any air bubbles out. I have been vaping on and off for a couple of hours and still have not seen any air bubbles? What's wrong with my setup? My other tank bubbles every so often but the one that bubbles is a 3ml tank with another juice. This tank is a 6 ml tank. Please help with any knowledge it would be greatly appreciated. Thanks!