CrazyCichlids;5081382; said:Ok so we know the tank size. Next important question is "Has this Oscar always been by himself?" If you answer yes to this question putting any fish in with him could be a big problem. Even if your oscar is mellow, cichlids that never have had tank mates or have been alone for months or years can have big issues with new fish being put in their environment.
The oscar isn't the problem its the flowerhorn. The oscar would get destroyed before the it did any damage to the flowerhorn.