I have a group of 8 young adults; two have paired off and spawned but paid no attention to the eggs. They spawned again last night ...at least I am assuming they did, as they are staying behind a log and chasing everyone away. Hope to raise some of these fry.
Radek is right that they would not work with frontosa, these need cool water temps. I keep them in an unheated tank. The pair in the pic were born in my pond last summer where temps slid into the 40s in fall before I brought them in .
I don't find them particularly aggressive, except when spawning. They have been sharing a 30 gal tank with larger Gymnogeophagus gymnogenys Rio Yerbalito comfortably all winter, I removed the Gymnos after the spawn, as they were pinned into an upper corner.
I tried to keep this pairs 5" parents with Madagascans and grammodes for a short time, and they were overwhelmed and died.