When the mixture looks transparent and draws without any trouble I view it as usable. One premium option ranks highest yet that alone does not imply the rest fall short.
Being pretty new to this whole thing, I started out a couple months back with some sterile water that came with my kit, and it had no label so I don't know the maker. After looking into things more, I picked a different kind that had good feedback online. Lately I found out about yet another option and got some of that. Now I'm thinking maybe I should throw away the stuff I already mixed with the one I chose earlier, even though nothing's gone wrong yet. Still, it's making me anxious.