I got my Smoketech U-DCT tank from VaporKings Smoktech LARGE ULTIMATE Dual Coil Tank (DCT) it's the clear one. The carto that came with it was fine and it vaped great. I filled it just a small way to try it out and then decided it was good to go. The next night I wanted to switch out flavors but I got different cartos to go in it that gave me real problems. They were these Cartomizers 2.6-2.8ohm 510 SCT-V2 I got from VaporPhoenix Replacement Cartomizers 2.6-2.8ohm 510 SCT-V2. I wanted to get them because they had a nice big hole. But they didn't have the locking flang and I noticed that my juice was leaking badly out of the bottom. I lost a ton of juice. Then I got these Single Coil Dual Punched Cartomizers, 1.7 ohms from MadVapes Tank Replacement Single Coil Dual Punched Cartomizers, 1.7 ohms. They do have the flanged bottoms and fit right. But they had two issues. First they either gurgled, so I blew them out, then they gave dry hits right after that. There was no happy medium on them. Also, when blowing them out, I noticed that all of the juice was also coming out of the tank and it was becoming emptier and emptier each time I tried. Drip gurgle, blow and dry hit...over and over. Then I got the CE2 style DCT tank cartomizers from Hoosier E-Cig and it started working better. I was happier. I was sad that I had no luck with real cartos and was back with a tank and wick, which is not too different than my Stardust that I had, just bigger. I also got this Chrome DCT Refilling Drip Tip from MadVapes because it was pretty and functional, but then my tongue was getting fried with little electric shocks, so I stopped using it. Now I notice that my tank is the large one and holds 6ml juice, but when it gets slightly less than half full it starts gurgling and leaking out of the bottom. Why would this happen? Has anybody else had any experience with this? Is this just a matter of having bought bunk cartos? Are there any good cartos I can buy out there that can be good with this tank? Also does anyone have any recommendations for filling it properly. Help!!