Phentermine

hi mate,just about every atomiser, cimrotaser, clearomiser, rebuildable etc? etc will see the coil turn black pretty quickly and its just par for the course .as long as it still produces good vapour and flavour then personally i wouldn't let it worry me so in answer to your question, unfortunately I'm not aware of any type of atty that will last about 30 refills without turning black cheersscott