oscar cichlids

Question
i have a 65 gallon tank. i have 2 Oscar chichid(which are about 4 or 5 inches long), a manganese cichlid(which is about 8 or 9 inches long), a jack dempsey cichlid(which is about 3 or 4 inches long). the manganese cichlid often attacked one of the Oscars and left the other one alone. however, today i went to feed my fish and i noticed that the manganese had attacked my other Oscar very badly. she tore some of her fins off and both sides of the Oscars body is exposed and tore up but was not bleeding. i immediately started to cry because it was so BAD. so i ran to the kitchen and got the water drops that removed chlorine from the water and added some to the water. it says that it has a slime coating for the fish and that it would help repair damaged skin.as for the other Oscar, the manganese tore 3 holes in his bottom lip and 2 holes by his nose and tore up one side of his body. so i took an old lid to another tank that has a screen in it and i put it in the tank right down the middle and separated the Oscars on one side and the jack and the manganese on the other side for now. i have had all of these fish for over a year and they have always been in the same tank. the manganese never bothers the jack dempsey. i feed them pellets everyday and i give them live feeder fish every two weeks. i usually buy about 6 dozen feeder fish. however, it has been about a month since they had live fish. today when i went to feed them and noticed all this stuff was going on i continued to feed them and the Oscars wouldn't eat. they have either been laying on the bottom or floating at the top of the water on their sides. my questions are: is this normal? why is she doing this to my other fish? will my fish be ok and live? how do i get her to stop? should i put her in another tank by herself? please if there is any way you could help me i would be very grateful. my fish mean a lot to me and i love them a great deal. i have had them for over a year and i got them when they were really small. practically babies. i would like to keep the all around as long as possible. i am really worried about my fish. please help me and tell me what to do.                         
                               thank you,
                                        Jessica

Answer
Hi Jessica,
  The problem is that as your fish get older, they get more territorial and that won't go away.  In general, I do not recommend keeping those fish together.  I strongly recommend keeping oscars only with oscars.  The managuense is going to get much too large for those other fish soon.  Basically, you need to separate them.   Sadly, if the damage is as bad as you say, the odds of the oscar surviving are not good.  Sorry.  

-- Ron
  rcoleman@cichlidresearch.com
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