I don't know what ingredients the liquid some of you folks are using that 'settle'. Water, alcohol, PG, VG, all flavoring I know of...are entirely miscible. I found a few bottles recently that have to be at least 7-years old, just sitting in a box for years. I don't think I'll use those remnants, but there was nothing particulate settled out. As I mentioned in an earlier post, if my liquid was settling out, I would be very concerned about vaping it anyway, not to mention fouling my coils quickly.