This is kind of a dumb question but I've read on several betta tanks about some tanks being too large for a betta. I've seen no reasons why though. Last week I bought a dragonscale halfmoon and put him in my basically empty 40 breeder planted tank. The tanks mates he has right now are some shrimp, snails, 3 killis, and some L201. He's really slow to eat so I'm scared to add many more tankmates. I just want to make sure the tank is suitable.