I'm confused at what water conditions a datnoid needs to be kept in? I've heard all different things and then I was under the assumption for a long time that they needed brackish for life, but now I'm hearing most people keep them in freshwater and have healthy dats? Can someone confirm this for me?

Yeah freshwater is ok, most dats live in fresh in the wild I believe? Fish stores tend to think all dats need some salt but it's just not true. There are a couple of brackish dats but they do just as well in freshwater.