The gurgling issue and leaking issue is as I said before. If you are able to cover the slits and it goes away you are fine but if you have tried that and have gone through a few new cartos then it is the juice you are using. If you are using two juices mixed together and one is thicker than the other it will flood and not work. If the juice is the wrong consistency it will flood and not work. I went through 9 cartos thinking they were all bad then realized it was the juice I was using. I took 3 control cartos and filled each with a different juice. the carto with the juice I had issues with before leaked and gurgled. The other two were just fine. It is something about pressure or weight of the juice. Maybe the thicker juice separates and pushes on the thinner juice causing it to flood or something like that. It is strange but it seems to be the cause unless you just have a bunch of bad cartos or you are getting juice in the center tube.
I've used 100% PG, 100%VG, 50/50 mixes, 60pg/40vg, and 70pg/30vg mixes without having any problems. I haven't had any leaking for the exception of one carto but that was my fault. I cut the slit too deep and tore the airhole (or jarred it enough to cause it to tear). As for the juice, I haven't had any problems using the different mixes with the tanks.


