I got a male red devil that bites me. When cleaning his tank I partition off half the tank so I can get the job done without the worry of him getting him. He also rams the front of the tank when my kids look at him.
I got a litlle female red devil in another tank which I hope to breed. She is not so bad but cant be kept with anything smaller than 4 inches.
I tried the male once with a full grown oscar but it stressed the oscar too much. He was scared of it. My male red devil is 6 inches and the oscar just under 12 inches.
So yeah Red devils are really meant to be kept on their own. I have heard though that in tanks of over 300g they can be peacefull.
Also you know they grow just as fast as oscars if not faster and require a large tank as some can get over 14 inches.
If I did not like the look of them I would have gotten rid of mine as like you I found out the hard way with it killing tank mates.
Hope it works out for you
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TONY The Proud Aussie
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