Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Well, each set up is a different story, but here are a few ideas:
1) get the shrimp established first. A big, breeding population will survive longer.
2) Some Bettas are more top oriented than others. Some won't go too deep into a tall tank, so the shrimp and fish might not meet.
3) Some Bettas are dedicated predators, and will spend their time hunting the shrimp, once they figure out that the shrimp are down there.
4) Good that you have a back up plan. If you notice that you cannot see many shrimp any more, they are hiding or getting eaten. Remove the Betta while there is still a breeding population of shrimp remaining.