Thanks all for tips and advice but i have been successful in keeping a 4 in oscar with breeding cons. At first the male con would chase the oscar out of his turf but as time went on the oscar would stand up to him. As a result the fish learned to live with each other without any craziness once in a blue moon the male con would try to battle the oscar but the O stays his ground. So far the cons had two litters without any incidents with the O.
Thanks

I also have a breeding pair of convicts in a tank with a 6 1/2 inch oscar and 5 salvini. The convicts do defend their babies very vigorously. The oscar does not come too near their end of the tank and when he does he is chased off. He takes no notice of them if his food goes up their end and they ignore him in the main unless he shows an interest in what they are doing. The convicts are a fascinating fish and very spirited.

I know this is a little late to respond but I have 7 Oscars and 3 male convicts together in a very, very, very big tank... Everyone gets along great, and the only reason I found this out was that I was given the convicts and had no other place to put them... I figured the Oscars would eat them but they didn't and everyone feeds together and has their own space. I intend on building a pond to put everyone in before the Oscars catch up with their growth spert.

Hello,
So far so good. The male convict has turned submissive to my Oscar. The female convict she just wanders peacefully around the tank when shes not breeding. The only problem im having is the Oscar seem very relaxed around the baby cons. There two main reasons why i bought an Oscar for my tank. One was that i had an Oscar many years ago that i completely enjoyed having and i wanted to experience that again. The other was to control the breeding of the convicts. So far my Oscar has shown mild attention in eating the juves. So mild that the one inch baby cons seem to like swimming with th Oscar LOL! Ironically the baby cons seem to be keeping the con population down by eating up the next batch of juves. My Oscar doesn't know what hes missing Well it is what it is.

well ive currently got a 70 g tank with 2 juvenile oscars, 2 clown loanches and 2 convicts , im not sure whether they are male and female but all i know is that the bigger 1 of the convicts chasses and harrasses the other smaller convict which is really annoying as the smaller 1 gets hardly no food what so ever , no matter how many hiding places i try to create or how many caves i make the bigger one will always bully the littler one, any ideas onb what i can do to stop this?????
other than that the convicts dont bother my oscars at all or any other fish for that matter, he only harrasses the samller convict,

i know that once the oscars get big enough i will have to get rid of at least 2 of the cichlids, it will more than likely be the convicts as i dont want to get rid of my beloved oscars, nemo + dorey,
just make sure that you provide plenty of hiding places and re-treating space for the convict

There is not much you can do to stop the convicts being aggressive as its in their nature. If one is not getting food, is getting injured or hiding all the time and is miserable then rehome one of them