When this was originally written, all tanks were made to surround cartomizers. Since then, genesis-style atomizers, rebuildable atomizer/tanks and large-capacity clearomizers with replaceable head units have been introduced. These all are (or can be called) "tanks," but this article deals exclusively with Carto-Tanks. Why should I get a tank? I don't know, maybe you shouldn't. There are pros and cons to using tanks and, like anything else, they're not for everyone. Pros: Longer times between refilling (so you don't have to carry a bottle of juice around with you) Carto always has that "first vape" taste, until the tank is empty Cons: Longer times between refilling (if you're used to changing out flavours several times a day) Bulkier than a carto alone Can be more "fragile" than carto alone A bit more inconvenient to fill than a carto alone Steeper learning curve (though it varies greatly from one person to the next) In general, people use cartos because they find them convenient and easy, but most feel that the flavour drops off as carto "empties" and this leads to a "muted" flavour throughout most of the carto. Most people find that a tank prevents "flavour drop" and helps offset the muted flavour by always keeping the carto full. On the other hand, some people really don't like the added bulk of the tank or have problems finding the right balance of holes to feed the carto properly without it flooding or running dry. How do tanks work? Tanks are simply a way to automatically feed juice to a cartomizer. A hole (or holes) is punched or drilled (or a slot is cut) into the side of a cartomizer which allows the juice in the tank to automatically flow in as need to keep the cartomizer "topped of." The tank actually does nothing except hold juice, the cartomizer does all the "work." How long do they last? Tanks are generally not considered to be "disposable" items and are intended to be reused. How long they last is really dependant on the materials from which they're made and how careful you are with them. Oh, you meant how long before they have to be refilled. Well, tanks come in all sorts of sizes and people vape at different rates. A 3ml tank will obviously not last as long as a 5ml tank. On the other hand, someone who only vapes 2ml a day will get a day and a half out of the smaller tank and someone who vapes 6ml a day won't make it all the way through a single day on the larger tank. Most tanks range in sizes between 1.5 and 10 ml. Oh, you meant how long before the carto has to be replaced. That's not a tank question, it's a carto question--but many people find their cartos last longer when used in tanks than they do by themselves. Not everyone does, though, so expect a carto in a tank to last about the same as a carto normally lasts you before it needs to be replaced. Can I use (CE2's/clearomizers, IKV Fusions, Boge Fusions ) in M&P tanks? Yes. Well, not clearomizers. Any cartomizer that will fit a 510/901 drip tip and has a plain steel body will work. The pressure required to make a leak-proof seal has a tendency to fracture the plastic on the clear cartos, and the paint or stickers on the coloured cartos does not react well in constant contact with juice. But--if it's plain metal and fits a 510 drip tip, you can poke a hole in it and put it in a carto tank. How do I fill a tank for the first time? How do I refill a tank? How do I change the cartomizer? Please watch the videos on Mom and Pop's site. They can be found here Tanks - Mom and Pop Vapor Shop by scrolling to the bottom of the description (about half-way down the page). Some extra advice can be found here: http://www.e-cigarette-forum.com/forum/mom-pop-vapor-shop/301607-new-sub-tank-video.html#post6259104 And some trouble-shooting information can be found here: http://www.e-cigarette-forum.com/fo...277201-darnit-broke-new-tank.html#post5539826 If none of that helped you, jump on in the forum and ask. Your question has probably already been answered so feel free to search for it--but the threads can be convoluted, and specific information can be hard to find, so don't be afraid to just post your question, either. Help! My tank gurgles and there's no vapor! Help! My tank is leaking out the bottom of the cartomizer! Help! I keep getting juice in my mouth! Help! I push the button and try to vape but nothing happens! That's great! Well, it's great that you're trying a tank, anyway. But these issues aren't tank problems, they're cartomizer problems--if you don't understand why that is then please read the "how tanks work" section again. While I could answer these questions here (since you are using a cartomizer), people that don't use a tank probably wouldn't look in a tank FAQ for a carto question so I'd end up having to type everything twice. No, I don't have the ability to cut and paste on my computer, so shut up. Since you're also using a cartomizer you should also be reading the cartomizer section anyway. Smarty-pants. Are M&P's Mini/Sub Tanks really the best tanks you can get? Really. You're in the Mom and Pop's Vapor Shop sub-forum and you're asking me that. Well, honestly, it depends on what you want in a tank. They are really some of the easiest to use and they are really among the lowest-priced. If you've never tried a tank before I believe that M&P's Submarine and Mini-sub tanks are the best value as far as low-cost, convenience, and learning curve. If you normally vape several flavours a day and would like to have a tank for each of them filled and ready to go, I think M&P's tanks are perfect. If you want a tank with colored or stainless steel end-caps to match your PV, or you want a tank that will survive being run over by a truck, or you want hand-blown glass or a customized, personalized logo etched into it, you won't find them here. They will cost a lot more, but if that's what you want then Mom and Pop's doesn't have the best tank for you. On the other hand, if that's where you think you want to go but you're not sure yet, the Submarine and/or Mini-sub Tanks are a great place to start.