I vape. Got a killer sale from a vape store that is going out of business, but not my regular nicotine levels. I got 5 bottles of 0mg/30 ml and 5 bottles of 18mg/30ml. I normally use 12mg. Trying to figure out the math to get to 12mg. I know if I split a bottle of 0 and 18, I'd get to 9mg/30 ml. So, maybe 22.5 ml of 18mg and 7.5 ml of 0mg get me there?