No excuse needed. A carto tank is a cartomizer with holed punched, lazer cut, or slit into them, surrounded by a tank held in place by o-rings, or end caps of some kind. You prime the carto (fill correctly), slide it into the tank, fill the tank, and vape.
SMOKTech Pyrex DCTank Glass DCTank
These are the ones I use, but IBtanked makes the best. You can even get cheaper ones to get your feet wet. A lot of people try them, and don't go back to clearo's. Usually the step after that is rebuilding, but it's not for everyone.
IBTanked is awesome. Great customer service. I was in direct contact with them regarding an issue I was having on their website. I have 6 tanks from them, but don't forget about Phiniac either. They're more expensive, but I've got 4 of them and they're very well made products as well. Personally, I've gone from carto tanks to clearos. When I first started vaping, it seemed all the clearos I tried were junk. Compared to carto tanks at the time, they delivered little vapor and what they did deliver tasted more like burning silica or cotton than liquid. I just recently decided to try out the Kanger Aerotank Mega and the Aspire Nautilus and love them both. I don't even use my carto tanks anymore.
Shellie, there's absolutely no building involved with carto tanks. Just like mentioned, you simply fill the carto with juice as you would a regular cartomizer. Then you slide it up into your tank. Fill your tank with juice, pop on a drip tip and vape. They're quite easy, especially with handy tools like the Slap Yo Mama Adapter from Big Daddy Vapes (thanks Baditude).
To the op...mjmag, I've got both the nautilus and Aerotank Mega from Kanger. As far as vapor production and flavor, I'll be honest, I don't PERSONALLY find a significant difference. In my opinion they're both well made, solid tank systems. Some prowl will prefer one over the other claiming the heads are better or last longer, etc.. this is ALL SUBJECTIVE TO INDIVIDUAL USE. How you vape, your mod settings, your liquids, all factor into that as well as many other things.
I'll just present some info for you to ponder on before ordering. First, yes the nautilus heads are more expensive. And I've run into a bad head already for it. As opposed to the NEW Kanger heads for the Aerotank Mega, which are cheaper and I've yet to get a dud and I've had it longer.
Some things about the Aerotank Mega, first of all, filling it completely (as directed) and then screwing on the base, when you turn it right side up, half your liquid drains into the base (as it's designed to) there's a work around for this (I wish I could find the thread to give credit) that involves pushing a Q-tip up from the driptip end, letting it barely come out of the shaft so you can fill the tank BEYOND its normal 3ml capacity. But I'm not sure what it's actual capacity is by doing this, as opposed to the nautilus holding 5ml without having to pull any tricks on it.
Another thing between the two is the airflow adjustment. As you know, the nautilus LOCKS into positions over a series of different sized holes. With the Aerotank Mega, there is only one hole and you twist the control ever so slightly until you achieve the airflow desired. There's no locking function, it can simply keep twisting around the base, but there is enough resistance to keep it in place during use. The only time I have to readjust it is after I refill the tank. So not a big deal unless it's something you don't think you'd like.
Those are the main differences, in MY opinion. Capacity and the way you adjust airflow. Personally, I love them both. Because of its capacity and locking airflow, I take the nautilus when I leave the house. But my Aerotank Mega I walk around with constantly at home with it on one of my mods.