community tank problem

[honda237]

I have been trying to get my 125g tank going for a few months now but i have had alot of problems. It seems like one or two fish get really agressive and beat the snot out of everyone else. They are all small around 1"-2" but they are all suppose to be peaceful. I am trying to make a breeding pair of red ceibals, i got 4 of them and 3 were bigger and more aggressive than the small one (hoping to be a female) but one of the larger ones was killed by the two bigger ones and i had to move the biggest one cause he got way to aggressive. when i moved most of the fish from a 10g they did well except for my keyhole, notatus and the pasiones. I dont know if they get scared of the bigger tank and freak out or what. the water is fine. Now my acara beats up on everyone. I am looking for help and advice so if any one could help me that would be greatful.
My stock is:
(3)Australoheros sp. ‘red ceibal’
(1)Cleithracara maronii
(1)Geophagus altifrons
(1)Geophagus brasiliensis
(1)Aequidens sp. ‘Atabapo’
(1)Thorichthys pasiones
(1)Heros notatus
(1)Heros sp. ‘rotkeil’

 

[HiImSean]

do you have different hiding spots like rock piles or driftwood? the brasiliensis will become much larger than the rest and more aggressive. they are all trying to establish dominance

 

[TrikkyMakk]

Have you tried adding some dithers? Silver Dollars are great (in groups of 6 or more)

 

[honda237]

i have a some hiding spots but it seems like they dont care about them they are always out in the middle of the water but when they go to hide they all seem to want the same hiding place. no i havent tried any dithers yet. I would buy some silver dollars but i really dont want them in my tank and plus their $8 for 1.5". i do how ever have a gold fish in there. i might try adding some holey rock. the brasiliensis is a little bigger than everyone else but he is like the piece keeper in the tank.

 

[sick_lid]

Being that you have a lot of different species, I would go with Sean as they are trying to establish some sort of dominance in their new home. What is the place where they all hide? Try making a few spots with the same type of setup, on opposite ends of the tank. The only aggression I see in my eartheater tank is between the smaller ones, around their log.

 

[honda237]

I did some work and put a lot more things in there and so far they are doing pretty good. I know it doesnt look the best but its working very well and yes that orange thing is a goldfish. sorry for the quality crappy iphone pictures.