I started at 18 in a tank on a battery, then lowered to 12 in tanks. (edit: over ~2 months)
Then got a mod and dripped 12 for a very short period of time, moved to 6, now am at 3, and am consuming so much/starting to get nicced out quicker these days so am considering a drop to 1.5 even...

(edit: over another ~2 months)