I understand your frustration. I'm a newbie. About 7 weeks now. I have ego twist batteries and I had issues and have tried different tanks. Vivi Novas, mini Novas, Kanger mt3 and boge tanks. The first boge tank I got was the f16, I wanted something thinner, but it didn't matter, I flooded it, it leaked, I hated it. A lil while later I decided to try the boge again but got the new f17, a thinner version and was given good advice as to how to fill them. I love them. Have many f17s since I have many different favorite juices. I don't have any leaking issues. I don't usually tip my tanks upside down and I keep them in a case in my purse. So right side up and on their sides I haven't noticed any problems. If you do decide to go with a tank, I will pass on the advice that was given to me. It works for me.... Remove drip tip, pull down the carto enough so that you can slightly tilt the tank and fill the
juice into the tank without getting
juice into the carto. When you're done filling, slide the carto back up, tilt the tank a lil bit again and drip a couple of drops down the inside of the carto, so it drips down the side and doesn't go right in the center of the carto. Put the tip back on. Cover up the hole on the bottom of the carto with your finger to seal it and take 5 good draws. You'll see the
juice go down, the fiber in the carto is obsorbing it. Don't draw too much. That floods the carto and it will leak. Good luck. Hope this novel was a lil useful.