If you want clouds with a Kayfun style deck get a lemo2 or subtank mini and use the RBA section .The air flow is just not adequate to support sub-ohming with a Kayfun unless you modify it but why trash a good atomizer when so many cloud tanks are available. I use my Kayfuns from 1.0-1.5 ohms ( I own and use regularly five; 2 lite plus's,2 V4's and a mini). also 18-24mg nic works ok to help you out in an clearomizer because the vapor production is weaker . but when using a superior tank such as a Kayfun 12mg would be MAX nic I would run in one of those the throat hit would be much to harsh otherwise .When I started using Kayfuns a year ago i promptly switched to a 9mg strength and within a month was using 6mg and thats where I have stayed in my Kayfuns . 12mg would make me cough now even at 1.2 ohms id be scared to hit it at .5 talk about a choke you out vape .at .5-.6 ohms you might even just be burning your wick at that low of a build. The primary reason we all started vaping was to stop smoking tobacco don't start smoking cotton.