I have read from others and just found out first hand that some of the issues pertaining to the sub tank mini are due to bent shafts going from drip tip into coil inside the tank. Mine came bent straight out of the original packaging from kanger. If you notice any restriction while screwing the airflow base onto the glass upper piece then I am pretty sure you are experiencing major leakage as I am. The fluid is passing around the stem and top of coil and going straight to the air control valve and all over your mods. Very poor design that kanger has come up with this time. Seems like they are going into regression instead of progression. Fed up with kanger at this point.