Add More Cichlids?

[duanes]

Agree with J.H, Hemichromis (Jewels) will eat your cardinals and probably take issue with your Acaras territorially creating problems.
And because they are African, I find them not correct to be in an otherwise South American tank.
But if your not concerned about geographic correctness, there are some dwarf African cichlids that may work, such as kribensis.
Keyholes are not aggressive, are South American, and may be (as suggested) a good choice.

 

[Bozatronia]

Agree with J.H, Hemichromis (Jewels) will eat your cardinals and probably take issue with your Acaras territorially creating problems.
And because they are African, I find them not correct to be in an otherwise South American tank.
But if your not concerned about geographic correctness, there are some dwarf African cichlids that may work, such as kribensis.
Keyholes are not aggressive, are South American, and may be (as suggested) a good choice.

Thanks! What about threadfin acaras? Would a couple of them work with the acaras I already have? I'll either do two of these or two keyholes I think.

 

[duanes]

Acarichthys heckelli (Threadfin acaras?) may be what you mean but common names mean different fish in different places? get way too large for that tank.
A young one would work for a little while, but at maturity they get very aggressive in a "too small" tank.
Mine started killing each other in a 150 gal, at about 2 years old.


Compare the Guianacara in the background to the Acaraithys.
And below is the size of the Guianacara, in my hand.