Just wondering if it needs that much water to function ? Very unfamiliar with glass - but more water means less taste which is bad for me at least. Hope this isn't the case as this looks great otherwise.
In general, you are correct you want low water levels in a design, but no, a high water level is the point of the diffusion pump design. They actually have very low diffusion which retains maximum flavor from your vaporizer (or dab). The DP design is one of my more favorite perc designs for vaporizers, especially when you're a flavor savor kinda person.
That said, I'm a bit concerned about these Chinese knockoff DP's. Look at the ball in that video, is it supposed to rise and fall like that? Every official bates & worm DP I've seen seems to cause the ball to rattle around much more violently than in that video.
Anyone with the origianl B&W DP care to chime in?