Iv got 3 rainbow snakeheads in a 4 foot 250 litre. There are in there on their own. They need a species only tank and are sub tropical. Ideal temp is 19 degrees c. They need lots of plant cover and hiding places and dim lighting. It's best to get about 5 or 6 of them, let 2 pair up and then re home the others. Use a sand bottom. I dont tend to see much of mine as they spend most of the time hiding. When I see them it's either because they come up for air or it's feeding time. Rainbows (channa bleheri) grow to 6-8 inches and they do have teeth. Mine rip apart prawns and river shrimp like its nothing