My brother tried one of these with his betta. It disappeared on him. Literally. We think it may have escaped and been eaten by his cat.
In the mean time, he had a heck of a time keeping it healthy.
They're really hard to feed properly-- if you see them wiping down the bottom of the tank with their fans, they aren't getting enough food. Modern filtration removes most of the particles small enough for them to eat, even if it does provide good water flow. They need a place to perch somewhere with good flow so they can open their fans, and well established tanks with lots of microfauna or cultures of small foods (like for fry). A lot of them starve to death, just slowly.
Shrimp tend to be very sensitive to ammonia spikes, so crushing powdered food will often do more harm than good because it's not distributed very efficiently & most will decompose and cause your water params to change.
Sorry to be such a downer. They're really cool & I wish they were easier to keep. I wish you luck with him. :)