Ok now my tank is at issue and that is not cool. I have established my little goldfish tank. 40 Gallon and have been slowly stocking it since it cycled in. I started with one fancy and he was all good. Lots of cover in the form of artificial plants for him. Had a real plant but well I can kill silk so real one died too. Anyways after a while of him in their I moved in my black moor he is happy in there and the two of them have gotten along like best friends since. No concerns with them for almost 2 months together (for those worried the moor is hand fed so he gets to eat.) Both are still very small. Anyways so fancy and moor no problems. Now with tank established I decided to finish it off and add the last fish to go in with them so I acquired another fancy (they are both red ryukin I figure from what I have read). New guy is about a quarter of a fish larger than the other two but not much with long flowing tail. Well it seems the old fancy doesn't much care for this as it is being very aggresive towards it. Whenever the new guy swims near one side of the tank the fancy goes after and starts bumping underneath the new guy until he chases new guy to middle of tank. The new guy looks terrified and starts swimming away as soon as fancy looks at him. From everything I read this tank is a great size for three fancy goldfish so what is the issue? Any help greatly appreciated!