I've ben using clearos almost exclusively for about a year now and while the type of juice is a common cause of cracking, I've also noticed that sometimes they do seem to develop small cracks on their own over time. Usually, this happens down towards the base and it doesn't really cause any leaking problems right away. Whenever I notice one starting to do that I mentally designate it as "home use only" so that if the leaking suddenly gets to the point that it is no longer usable it's most likely on a surface that I can wipe up without issue. I started doing this after I had one suddenly start leaking severely in my pocket while I was out. I don't know what specifically you are using but Ive found I have the best luck with the Vision clearomizer version 3 from AltSmoke. they are really cheap, can be completely disassembled and any of the parts can be purchased individually should it need to be replaced. Also they don't seem to develop random inexplicable cracks as often as others I've tried. Hope that helps.