Thanks so much for the detailed info and great pics! You’re a wealth of knowledge and I’m always surprised by how many different species you’ve kept.I have kept 2 species from the gymnogenys group, sp. Rio Yerbalito, and sp.Paso Pache.
Never experienced aggression problems with either.
I never used tanks for a group, any smaller than 6 ft , and only kept one species of the genus per tank..
The groups were always 1 male, to at least 3 females, and if a female was holding, she'd get her own tank.
I never used heaters in their tanks, just going with room temp.