Elyssa,
No problem. NYC water is some of the most conducive for shrimp raising and in my experience it has definitely not dissapointed. And to answer your question - yes I have been using the same NYC tap water in both of my tanks.
So because the eco-complete tank has been having much higher pH's I have been using indian almond leaves to buffer the high pH and further IALs are also great for the fauna as well. Of course, overall I wish my pH would just stay low in that tank by itself.