I have a 55 gallon show tank (longer and thinner than a normal tank). Hopefully it will be big enough or they will just grow to the size of the tank.

I mainly feed them goldfish but now wish I would've started with bloodworms or koi pellets. I've heard that once you "spoil" them with live fish it's nearly impossible to get them to eat dead stuff. The smaller one will eat the worms and fish but the larger one will only eat the fish.