About 4 months ago I switched from clearos to cartos, smok pyrex DCT with smok XL 1.5 stainless/2-3 hole pre-punch cartos. When I replace the carto I take that white rubber top thingy that comes on the top of each carto off & throw it away, but... I was watching a video on youtube today & a guy put that cap back on after he primed the carto! Can someone please tell me the correct thing to do? Thanks ya'll in advance!