Hello all! 
 
I hope this hasn't been covered already. I've recently started using tank mods, I really like them too, but I've noticed my choice of cartomizer is producing small black specs after some use (couple days). 
 
http://altsmoke.com/...zer-select.html 
 
This occurs shortly before the cart starts spitting hot liquid. What the heck is going on with these. Is it just a bad choice or is this normal for the DC tank carts or something I'm doing. 
 
Silver Bullet (3.7) 
DC 1.5 Cart 
PV 6ml-12ml 
 
Thanks