Crystals and other Caridina shrimp can be quite colorful and expensive. I've kept neocardina (reds, yellows) shrimp for a few years now and they are pretty easy to keep. I've avoided crystals because of their requirements: low pH, pristine conditions. Many folks use RO
water and mix it with a remineralizer along with shrimp specific substrates (that help maintain a low pH).
There are a few members here that keep crystals and other high end shrimp; perhaps they can chime in.