I would stay away from the VG at the pharmacy , try Heritage Brand, NOW Brand,,, RTSVapes, or some others,,,, the Hunco Brand and some others at Pharmacies isnt quite as good, not sure if it's the bottles they use ( Plastic ) or the actual specs, All USP VG is NOT the same. Also download a
juice calc, like Breaktru Calc or Easy-E-Juice calc these will tell you exactly how much to add, hope this helps. Also remember if your just adding VG to vendor purchased juice it will take away from your flavor some by diluting your juice with VG instead of ordering it with a higher VG or DIY'ing it with a higher VG %