angelfish killing other angelfish

Question
I have a 29g tank that has 2 med. veil angelfish(ones a platinum and the other a koi), 1 sm. halfblack angelfish, and 2 sm. albino catfish. The nitrates are at 20 and the ph is at 6.8. The problem is the sm. halfblack angel is killing angelfish that I put in with him. He is hunting them down in the tank and nipping them intill they fight back. If they run he really gets excited and just keeps at it till the fish is dead. I have had 6 sm angels his size die and now he is killing my 2 medium size fish. Right now the med ones are missing tail, and dorsal fins just since last night and they have been in the tank for a week and a half. I have tryed rearrangeing the tank, and I have over half the tank with plant for hiding but like I said he hunts them down no matter where they go in the tank. I have never heard or seen this behavoir before and I really like the fish so I don't want to get rid of him. I have a fifty gallon with 2 oscars that are full grown and I am really thinking about putting him in there with them just to see how he does but I'm afraid they will eat him. What can I do.  

Answer
Hi Michelle,
A 29g is quite a small tank for the Angels.  They need space especially if you have a lot of angels because these fish are considered semi-agressive.  The males are very territorial and I believe this is what is happening in your tank.  Angels must be kept in a 55g or larger, the bigger the better.  I wouldnt put the angel with the oscars.  I also believe he will be eaten.  The only thing I can think of is either to upgrade the tank, get another tank or give him away.

-Matt-