Not many of our members here are cloud competition folks... 99.9% are vaping for smoking cessation or hobby, rather than competition. If memory serves, from reading the local brochure from a recent competition (which I did NOT attend... never will actually), there were divisions, and listings of specific, allowable gear, as well as an "open-mechanical" category. If you want to compete, check with the local competition organizers for a recommendation of gear, and you can't go wrong, or you may show up with a sub-par (or disqualifying) rig. Some competitions only allow pure VG, some don't, so be aware of your juice limitations too. Pure VG gives the max vapor production, BTW. Personally, I think the cloud competitions are vaping's biggest enemy, and further damage vaping in the eyes of the pubic. Huge clouds look cool to some, but to most, they look dangerous, menacing, and disgusting... and the media and government LOVE to use photos of cloud-chasers to support their regulation crusade, so they can say "look at this horrible, death-cloud! We must regulate this and stop it... for the CHILDREN!". To each his own... but what you do in public casts light upon more than just you!