Thanks for the link . When this pressure differential in 'broken', what could have I done to to break it ? Often I can vape 1 or 2 ml of my tank's 10ml content before gurgling happens. The level in the tank does not seem to matter.
Yes, maybe I am drawing too hard and too fast...
If your clearos/glassos are fit with "stock standard" coil, with the standard silica wicks and stock air port system (or the same with a carto... but limited to the air ports) yes, they can be "overpowered" with a hard draw.
Ever notice how so many folks complain of their clearos/tanks whatever, have a tight draw? Block one air inlet... and you can overpower the wick/seal to an even greater degree.
When you have, what you perceive to be a tight draw, that's an indication that, for your vaping style, you don't have adequate air flow. When you take a draw, you're "sucking" hard enough (producing enough vacuum) to overcome the wick...
in it's function as a seal.
Follow? You draw hard... the air port system can only accommodate so much of that hard draw, with the remaining vacuum being applied to the liquid tank - via the wick and wick cutout. So... more juice than your coil/head & wick can support = flooding/gurgling.
When I started, I was like everyone else. Clearos... then immediately to carto tanks, which I thought, at the time, were the best there is. Then I got my first RBA, and the clearos and carto tanks collected dust.
Air flow, and the power to control wick/coil type/coil resistance/current draw... basically
everything... is the reason everyone who wants the best vape they can get, move in that direction.
With glassos/carto tanks, you can enlarge air ports (to a point) with drill bits - your choke points being the air tubes, coil tail retainers, DT and of course... the external, visible, fixed air inlets.
The alternate is to move on to glassos with adjustable air (Kanger Aerotank is reported to have good air flow, and perhaps the best glasso there is, for now)... or on to complete control with rebuildables.
Have fun! ;-)