Hi Agonize, I always fill my cartos before they go into the tank, As if they weren't going in a tank. That way I know its full and I won't scorch it right off the bat. The tank cartos have been really finicky for me and the single punched holes almost always need to be opened for me to get them to wick well. I have almost no faith in some guy in a factory getting the hole size correct for the liquid that I am using in my tank so I always aire on the side of caution. Second note is to pay close attention to the holes when you draw on the carto there should be some type of bubble(s) coming up through the liquid to show you its feeding correctly. Keep an eye on that so you don't end up with a bunch of dry scratchy burnt hits from your new tank. Good Luck. Happy Vaping.