When I was able to vape in my office (the Building Nazis have now forbidden it) I would go through maybe 6mL in my Protank 2s. (Puff2K, figure about 2+ mL per tank on the PT3 (as long as not the minis))
Now, I might get through one tank during the day (6-10mg juice), and maybe a tank at home in the evenings. If I'm hitting my Nanos, I might get a couple tanks in at night as well.
{wish I could vape in my office.....}
Since I rotate different flavors between Atlantis, sub tanks, and a Herakles on a Sig 100W+ and mini 2 daily I have no idea how much juice I am going through........which is probably a good thing!