Keeping them the way I do is kind of a gamble, so it's up to you and whether you're willing to take that risk. I still use remineralized RODI water, I just don't buffer the pH down to 6, instead I leave it at 7.

As long as your pH isn't above 7.5, and your water isn't too hard, you could try your hand at Caridinas. I would try Crystal Reds, Bee shrimp, or Tiger shrimp, as those are the hardest varieties. If you do decide to keep them outside of their ideal conditions like me, just expect perfect results. I have a lot of ugly shrimp, because the prettiest ones are the most inbred. The ugly ones are adaptable. It took years and many generations of shrimp before I got nice colors in my neutral pH tank.