My understanding is that the kangen water devices filter and alkalize. A friend had one for years (still does but he moved) and I would often fill my water bottles with it. I found it to be a good hydrating water, in the subjective sense that my body seems to like it. But the process would have no effect on the deuterium count, to the best of my knowledge. But I've gotten more curious about all this so will be doing more posts on the subject.