May i ask some tips on proper tank filling
If you are using a smoktek tank, the best way I found is to insert cartomizer through bottom, about 3/4 of the way to the top. Take one of our drippers and sort of angle the carto to the side so the drip tip will fit in down next to it (you don't want to get ANY liquid inside the carto itself.)
Fill the tank up to about as high as you can without over filling to the top of the carto, slide the dripper back out, straighten the carto and push it up and through.
Now it's full assembled and filled with liquid. You need to prime the carto by plugging the bottom of the carto with your thumb (push the bottom of the carto flat against your thumb) and then draw hard about 2-3 times. (well, not too hard) this will draw the liquid into the carto through the carto's holes (assuming you have pre-punched cartos, or perhaps have punched your own hole into a carto).
Be careful not to draw too hard or too much you do not want to flood the carto, just to get some of the liquid into a carto, if you are using an XL carto (like a Smoktech dual coil or even single coil flanged pre-punched) you will probably want to draw until the liquid is to about 1/3rd in the tank (if it was 2/3rds before). If you have a smaller tank, this drawing might take out most of what you just had in the tank.
Now your carto is wet and primed and ready to go, slide it back down so it's just inside the top cap, and "top the tank" off filling it one last time following the steps outlined in the beginning.
Finally, slide the carto up and through the top again, add your drip tip, and vape happily!
The above method is the one I have been using for many months and it always results in happy vaping. sometimes if you "set" the drip tip on the top cap and push down on it as you push up on the carto it will help make it easier for the carto to slide all the way through.
Hopefully this didn't confuse you to hell. You'll get the hang of it though
PS you can find some videos of this method on youtube, probably some other less worthy methods as well! (kidding)