Firemouths And Cardinals

[simonas]

I have 17 cardinals and was thinking about getting two 2-3 inch firemouths. I've kept them many times in the past but with bigger fish. What are they like with small tetras

 

[Byron]

Though quite peaceful for a cichlid, small fish are not advisable.  The medium to larger tetra, some barbs, would be better with Firemouths.
 
As you have the cardinal tetra, a good cichlid with these would be either of the "ram" species, Mikrogeophagus ramirezi (the common or blue ram) or M. altispinosus (the Bolivian Ram).  The blue ram is more delicate and needs warmer water, which the cardinals can manage with; the Bolivian is fine at more normal temperatures (77-78F).  A single Bolivian Ram is probably the most peaceful community cichlid with other fish.
 
Byron.