I've noticed something and was just wondering if I was alone or not. I use pre-punched dct's in medium sized 3.5 ml tanks. I use a 1/32 inch drill bit to enlarge the holes a little before I fill a tank with 'em. All is fine and dandy until the tank gets near the empty mark, let's say around 20% left. Then, the carto starts to flood, gurgle and leak onto my mod. To fix this, I obviously just keep my tanks filled up, but that sort of ruins the purpose of having a tank system in the first place, doesn't it? Am I alone on this, or has someone else experienced the same thing?