I completely agree with Bad^^^^.
I know that it seems like a Clearotank would be easier to use but a carto tank is just SO much better. The flavor of the juice and the vapor production are much better with a carto tank. Also it is much more cost efficient. A cartomizer lasts me about a month but the head coils on my ProTanks only last me about 4 day, and they cost about the same to buy.
I recommend IBTanked as well. They are my absolute FAVORITE tanks and the are well worth the couple extra dollars over the ProTanks. They are much cheaper in the long run.
They are super easy to use. Just buy the filling tool ($2.50) and they ship in a little plastic container called a 'thingy' and you are all set. SO easy to fill a cartomizer with the 'thingy'. I am slightly accident prone and I can do it with no problem, so I know that ANYONE can do it!!
You will be so happy with the carto tanks!!!
Good luck and welcome!!!