My brother has a 3.5 gallon that he wants to turn into a tank for ghost shrimp. It will have driftwood, a small airstone, Marimo moss balls, river stones, and Hornwort. We plan on getting 12 Ghost shrimp since my LFS sells them by the dozen. The tank has been cycled. How often and how large should water changes be? What should the shrimp have to eat? Any other tips to keeping shrimp? Thanks in advance.