Hi I'm new to the board this is my first post. I bought a baby silver arowana about a month ago, it still had the egg sack when I got it. The sack has disappeared and he has been eating krill 3 times a day. Recently though I have noticed he's been acting funny, swimming wobbly and such and his tail fin and bottom fin have black around the edges and the rest of his fun is brownish yellow where it is normally clear. Any ideas on how I can help him?