Like everyone else has said, the nic should be drastically reduced in a subtank. I went from an 18mg in my kanger aerotank mega to a 6mg when i got my subtank and segelei 100. Once I started dripping on mechs I went to a 3mg. Sub-ohming with a tank requires highly reduced nicotine levels to give you the same fix as a higher nic in a plus-ohm tank since the liquid is vaporized a lot quicker. And 100% VG should work fine as long as you prime and dry puff and let it sit for a few minutes. If the flavor is too muted maybe try a 90VG/10PG. Happy sub-ohming!