In my experience, Caridina shrimp almost require remineralized RO/DI to breed and start colonies. It seems the higher the grade, the more demanding the shrimp too. I've managed to get some to survive acclimation and live in my tap (which is soft and neutral) but in every case I've gotten them to make new shrimp, I used RO and special substrates. Neos on the other hand, seem to reproduce just fine in a wide range of tap water. If you aren't simply enamored with Caridina varieties, I'd go with Neos hands down.
Nothing good happens fast in an ecosystem.