Hi and welcome. Most Kayfuns have a grub screw in the base, adjusted with a hex key, to adjust the air flow. That said, Kayfuns are generally intended for high ohm, low watt, MTL vaping. They are intentionally restricted in air flow to accomodate this regime. In short, they are not built or intended for big cloud. There's a limit to how much vapor you can get through one. If you can't get the cloud you want, you'll probably need a different tank. If so, look at a Lemo2. It builds and wicks very much like a Kayfun, but has much better airflow and a subohm insulator.