The leaking and gurgling was an issue with the Kanger tanks once down to below 1/3 a tank on the Protank 1 and 2. Surprisingly the elasticity between air and the liquid in the tank creates a vacuum suction that prevents liquid from just pouring in when above 1/3 of a tank, get below 1/3 a tank the elasticity of the air and vacuum can't hold the liquid back. Amazing the amount of physics involved in vaping -_-". So just have to keep the tank above 1/3 to keep from flooding and gurgling is all.
Thank you for that answer, I am glad to see a scientific explanation as to why it leaks when it's low. Common thinking would say that when it's full there is more liquid volume and force on the bottom so it should leak then but when low there is not as much "pressure" on the bottom so it shouldn't but what you said makes perfect sense! I will just try not to let it get too low.