I'm at a loss for any other explanation. My pro tank II is about 10 days old and out of the 4 atomizers i bought, two leaked for absolutely no good reason. From what i can tell it's most likely the rubber/latex ring that seals of the the e-liquid from the tube to the mouthpiece, but it could possibly be the seal. The thing i can't explain is how i could possibly get 2 brand new atomizers that leaked. i tried rebuilding the setup, checking the seals, different combinations... the ONLY thing that fixed it was switching to another, brand new atomizer. Anybody else have such a problem? The tank itself works fine, some of the atomizers that came with it are garbage though (about 30%, maybe i got a bad batch though).