I had issues with the J Tank leaking at first, but once I figured out how to fill it, no issues. None with my Liquinator either. Question: once the liquid gets past the holes, I assume you have to fill again? I've never let it get past that, I just keep adding, but wondering. And how long does a carto last before I need to put on a new one? I've not done so yet, since I got it, about 3 weeks ago. I have so many other methods to vape that I haven't had need to swap out.