DTL or sub-ohm vaping uses thicker high VG e-liquid, which is available in 10ml bottles of premixed nicotine, or the more popular and economical 50ml & 100ml shortfills, that start out with 0mg of nicotine and leave room for an additional nic shot.
Here you are inhaling deep lungfuls of vapour through a kit that pumps out double or even triple the amount of power to that of an MTL kit.
You can see where we are going with this.
These high VG e-liquids can contain up to 3mg or 6mg of nicotine, but quite often people vape for the rich flavour and sheer recreational fun of blowing out massive clouds of vapour - so things can get a bit carried away.
More power means bigger clouds carrying denser & more complex flavours. So you can bet that those sub-ohm coils will be drinking up your e-liquid fast.