Arguing about water

Also from that same post that provided the previous link, is this rant by someone who wants you to know that H2O is not water. Here, I'll let him say it.

It is a straightforward fact, corrections to it are endlessly ignored, but it is simply false to say that water is H2O unless we are speaking very, very loosely.
...
A glass of water, pure as water can be, is better understood as containing H2O, OH–, H3O+ and other related but less common ions, and even this is a vast oversimplification (if we could get truly pure water, which we cannot). Our current best understanding of the electron transfers that give water the properties we observe is a statistical average of ever changing interactions so complex as to be quite literally unthinkable. Indeed, the problem is “not that we are unsure which (distribution of types of) microstructure is the correct one. The point is that there is no one correct microstructure, because the microstructure depends as much on the context and functions just as another nominal essence would” (van Brakel, 2000b, 80–81).

I think it's fair to say then, that water is H2O unless you're speaking very, very pedantically. To me, this is like those folks (though I did enjoy the topical pop culture reference at the end of the video) who get so worked up over the concept of "Π" and insist that we should use "Τ" instead. They'll tell you Π is wrong, but really they just find it less conducive to the way they think. Which is fine, but not the same thing by a long chalk.