I have 2 30ml bottles of a Menthol e-liquid, both from the same vendor. One is 12mg/ml (too weak for me), the other is 18mg/ml (a bit too strong, makes me cough). Both are 100% VG Based. If I mix equal parts of both (say 5ml of each) do I get a 15mg/ml juice or does some other factor come into play? Iwould like to use this juice, but neither right now is good for me, thanks hfm