Geophagus Aggression Consultation

[tetraodon_biocellatus]

Hello all,
 
     I have a 125 gallon aquarium stocked with three 2.5 inch geophagus altifrons, five medium spotted silver dollars, one 3.5 inch Threadfin Geophagus (Acarichthys heckelii), and a 6 inch Geophagus brasiliensis. The Geophagus brasiliensis rules the tank with an Iron Fist as he is roughly twice the size as the second largest fish (the heckelii). Over the past few days he has been ruthlessly beating the threadfin geophagus whenever he comes out of hiding, the threadfin currently resides behind the powerhead as it seems to be the only place the brasiliensis can not get to him. His caudal fin is badly torn and he has constant stress colors. I am considering moving him to my 55 gallon, but i do not want to stunt his growth. The tank is also moderately planted and i don't want him to destroy my plants. And even then that would only offer a short term solution. The other option I am considering is mail ordering 3 more threadfins to distribute the brasiliensis's aggression. I really dont want to get rid of my brasiliensis if I can help it, and Im wondering if he will attack my altifrons once they get bigger. Does anyone have any advice on my course of action or insight on methods to reduce aggression? 
 
Also the aggression seems to come in spurts, sometimes the brasiliensis completely ignores him and other times he is in hiding or being chased. Events such as this have happened in the past and the aggression seemed to subside after a few days. 
 
The heckelii is my favorite so if push comes to shove I can probably part with the Brasiliensis though it was a gift from my grandfather and I am very attached to it as I have raised him from a very small subadult. I also dont want to doom the fish to my LFS so help is greatly appreciated.
 
Thanks! 
 

 

[Akasha72]

Hi,
 
You could try changing around the decor - this will mess with their territories and sometimes it can help to calm things down. If that doesn't work you may have to decide which fish is the most important to you. Is there space for another tank in your home? Perhaps then you could split them up but still keep them both. I wouldn't add any more but someone else might have another opinion

 

[malfunction]

I think you're always going to have aggression issues as both heckelli and brasiliensis tend to be amongst the more aggressive of geo species. I've found that brasiliensis is generally a terrotorial fish that likes to dominate tank mates. I've yet to keep heckelli, but I've heard that they're also very dominant, especially when they get older. Even more so when they pair up, so I think adding more heckelli would just cause more fighting.

Personally, I wouldn't mix those two geos, but you have a big tank so it might work. Perhaps you could try rearranging decorations to break up their line of sight?