What crxess said.
Somehow, some way, there is a point to providing liquid to a coil and doing it at an appropriate rate. That is the point of all wicking - be it in the coil, or in this design - on top of it as well. Simple geometry - you have a round coil, being sealed on top by the flat surface of the bottom of the vent tube. Oh - that doesn't exactly seal does it? If the top wick isn't there you get a flooded coil where vapor production actually goes down, not up.
Well at least somebody doesn't understand how to vape maybe. The biggest problem I see new users having with these Kanger bottom coils is running them as hot as possible, just because they can. The technology neither works well or needs high voltage to "blow your clouds, man." I have a PT coil metering 2.5 ohms and I'm running the thing at a ginormous... 3.7 volts. With 100 VG liquid with the top wicks in place. Guess what? It works. Run these coils at what the "know it all's" think the voltage should be - because they know everything about how every piece of hardware works - they read something about watts and stuff - and then we have the 137 threads complaining about a PT, Evod etc. tasting harsh and burnt, and flooding because a "know it all" said the only way they work is with the top wicks removed.
Start the Kanger Bcc's at your lowest voltage possible, especially if you made the mistake - oops, "informed decision" - and headed straight for the 1.8 ohm coils. Don't be surprised if you can get your cloud thing working at an embarrassing 3.2 volts with a 1.8 ohm coil. I won't tell the "experts" on you. However, if you want to be an "expert" at vaping, rip the thing apart and modify the design before you even try it.