Depends how heavy you vape. Certainly sticks to the water surface. If your a bit of a cloudchaser it can sit on top of the water, though this takes some heavy smoking and no vents, after a good session there is always oil at the top of my betta tank, it being the only tank without decent surface agitation though.It must take a good hour or two of smoking a 70w heavily to actually notice a problem. Id still like to know exactly how it effects the water as surely it can do no good, been thinking about this for ages I am glad you brought it up. Hooligan massive point on it being a veg based with the glycerin, maybe it will dose my anubias up and I can drop the co2