Aggression Problems

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If they are the two most dominant fish in there than that could be why, they are trying to establish supremacy in the tank. You can introduce a bigger more aggressive fish but that is risky. Or you can add more fish of similar size. This will disperse aggression to other fish as well and not just to each other.
 
If they are the two most dominant fish in there than that could be why, they are trying to establish supremacy in the tank. You can introduce a bigger more aggressive fish but that is risky. Or you can add more fish of similar size. This will disperse aggression to other fish as well and not just to each other.

I think a better option would be to add a bigger fish that is NOT aggressive but can hold it's own with the other two. Maybe a large bocourti or something along those lines, but significantly larger (10"+).
 
Thanks for everyone's help, decoration only is temporary (2-3 Days ceasefire). I have a 3in GT, 9in Arowana, 2in Convict, 2 Plecos, 4in Oscar. The jag and dempsey absolutly are non-aggressive towards the little guys... Hell, the black convict shares a cave with the dempsey lol... I might try adding a bigger passive fish. I'll let you all know what the outcome is. Thanks again!
 
IMO you've already got some potentially large fish so adding another large fish might not be the best idea longterm. I'm not saying it works every time, but the addition of 6 large(3") silver dollars to my SA/CE community was like hitting the reset button on the tank. Don't know how long it'll last but for now it's working well. That and lots of sightbreaks and separate zones.
 
Kinda of the reason I like the geos. You can keep them together with out all the crazy agression. When most cichlids hit the 5 to 6inch mark the agression will start some even earlier. Grammodes comes to mind ( had 8nch male that was insane with any other fish). Try some large charicins in there. Good luck and remember thats what cichlids do.
 
It's not often that the answer is "move the fish to a smaller tank", but in this case I agree. lol

Agreed, you could try the other suggestions first if you really think it might help and to satisfy yourself you exhausted every option but in all honestly one of them needs to go. Weather that means keeping the JD in another tank or trying a different one of either species to see if that changes things those two fish will most likly never get along. As a matter of fact the JD or Jag may now hate any fish of the other species on sight now so that may not work either at this point.
 
Ill try adding a similar sized fish, see what happens. If that doesn't work ill go for the dithers. Worst case scenario dempsey will have to go, he is the aggressor. The managuense has no other problems with any other fish... yet.
 
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