My brother got a Marineland 5 gallon crescent aquarium system and wants to start a shrimp tank. We are going to keep a pair of Scarlet badis in the tank for shrimp population control. My question is, how many adult shrimp should we put in the tank? I have a larger tank with only five shrimp, but he would like quite a few. What's a realistic number for a 5 gallon tank?