South american Ovestoking

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JurassiConger

Feeder Fish
Mar 19, 2026
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Italy
Hi everyone,
i'm planning to fill my 180*60*50-70(it's curved)cm acquarium with a community of big south american fishes.
I've "adopted" one very big Leporinus fasciatus and one A. albifrons and a common pleco. All these are 30-40 cm now. They stay in a 150 cm tank with my polypterus delhezi, some bristlenoses and a couple of Australoheros red ceibal.
I'm planning to move them in the bigger tank but i also want to put some cichlids with them. The leporinus is kinda a bully (fin nipper.. and not aonly fins. as the pleco has only one eye now) so no small or peaceful fish.
I was thinking about trying to put eith them 6 Geophagus brasiliensis, a small group of silver dollars, 4 oscars and maybe 4 heros/smaller cichlid.
Obviously the filtration and ossigenation will be massive and on the two sides will be put a forest of hedera wood (i find it very hardy to loricaridae grazing and perfect for create a shelter without taking too much swimming space) and roots of live plants (mostera photos etc).
The general idea is to create a community tank overstoking cichlids to avoid/mitigate aggresive beahviour.
Final population may be something like: 6 geo, 4 oscar, 4 heros, 6-8 metynnis, 1 leporinus, 1 black knifefish, 1 pleco. maybe some bristlenose/small ciclids (more as food) and h. thorchatas as bottom dwellers.

Anyone did similar things? Can it work? Other species are better? I'm kinda sure about geo and oscars, both semi-aggressive and around same size (maybe better 4-4 numebers, being brasiliensi less schooling fish than other geos) not totally sold to heros. (green terror maybe better choice?)
 
Thinking of each fish as full grown, I believe the tank is too small for all those fish. For example, if you really wanted Oscars I would have just one, with a school of 6-8 silver dollars, and a pleco. Good luck.
 
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Completely agree. Too many large, and some boisterous fish. The tank is a nice size, but not huge. The Leporinus will probably also harass the dollars and maybe others. The suggestion of a single Oscar is sound. Good luck!
 
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Overstocking doesn’t really work with sa/ca cichlids the way it does with Africans. If anything it just makes them more angry.
If you have any hope of having a community, get rid of the leporinus. They are among my favorite species, but are very aggressive, especially towards other large fish like cichlids.
The knife fish would probably also struggle to compete with the more boisterous cichlids.
 
I agree with the others, far too many fish to live properly in an around 200gal aquarium.
You may be able to do one oscar, one brasilliensis (these are nothing like other geophagus- behave more like Central American cichlids Amphilophus etc), one severum, with the leporinus and myleus. Trying to jam 4-6 of each of these fish into this size tank is going to have them cooped up like sardines, and make it almost impossible to keep the water clean when the fish are adults. Oscars are very prone to Hole-in-the-head especially when kept in conditions like this.
 
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As others have said, way too may fish, to me tha 2 oscars alone will max out that tank as adults.
But I am thinking in tems of cichlid climate diversity combinations.
The Ceibals and G braziliensus are temporite water species.
Image.jpeg
Amazonian are tropical species.
Cichlids like GTs, Ceibals and G braziliensus like cool downs, not drastic, but they do best with them.
images.jpeg
Above a snowy winter scene nearBuenos Aires, where Ceibal and Go brazilensus come from.
I get the impression you think one temp fits all, but S America is filled the diverse climate one, and hence, all cichlids do not fit in the same tank
1774891004065.png
I let Uruguayan tanks get cool quite a bit
No heaters in winter, yet this drop might kill oscars ,or those from northern S Amerca such as,
but is healthy for Argentinians and Uruguays

To me you have at least 3 separate tanks here, all separate temps.
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My adult Oscar was beaten within an inch of his life by a Banded Leporinus. The Oscar miraculously survived. Those Leps are tough, tough fish in every regard.
 
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My adult Oscar was beaten within an inch of his life by a Banded Leporinus. The Oscar miraculously survived. Those Leps are tough, tough fish in every regard.
I have some in my 450gal. They're not aggressors in my tank but when the green terrors or firemouth try to bully them, they are just not bothered at all. One wide turn of their long bodies sends the cichlids dashing away and then they just keep going about their business. Interesting fish to keep.
 
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