I've been wondering about this. Getting water right is one of the most complex and frustrating parts of fish-keeping, so we're going to have a lot of questions of that nature. I just created water-parameters yesterday because we need either that or water-quality.
I don't think it matters which we use. The two terms mean basically the same thing and are used pretty interchangeably, and in practical terms typing "water" will show either as a tag option. But these are the two options really, unless we want to get really granular with ph, nitrogen-cycle, water-hardness, etc. Strictly speaking, those are the individual water parameters that make up water quality.
One thing I've noticed, and the reason I went with water-parameters, is that people tend to talk about quality when they have a problem with bad water and parameters when they have a question about good water. Like, "What water parameters do pearly danios need?" vs. "Why is my water quality so poor?" But water-quality is a more common and inclusive term, and for what it's worth, public aquariums usually have what they call a water quality lab.
Edit: I think the two concepts are so closely related, it would be confusing not to have them as synonyms. If we needed a level of precision that would distinguish the two, we should have a high-level water-quality and more targeted ph etc. But I think that's overkill at the moment.
controlled-environment and chemical-balancing are not aquarist terms of art, so I'd vote no on them. water-chemistry is another option, but it's a little too specific: not all these questions will be chemical in nature.
