I feel silly asking but i started with a 10g and i moved everything into a 27 g a few months later. So now I got a empty 10g and a little bit more knowledge on aquariums. I want something more unique in the 10g I am torn between a shrimp tank or a betta. Also I like the idea of this But i believe it would get to big for my tank. Also i like fiddler crabs. Can i keep any small and cool looking Crayfish or crab in a 10g by themselves? I just want something more unique than just a community tank.