Great info! I’m not trying to breed, I am going for a display tank. I have 2 apistos which I thought were a pair, but I’m realizing one was a false female so I have 2 males in a 40 gal, besides them chasing each other here and there, they get along just fine. I don’t want to do a full community tank, just want to add a few more species to liven the tank up a little.Simple:
If you have a pair or harem (and potential breeding) - No other bottomdwellers. The problem mostly occurs when the Apistogramma are the most territorial. Often the females burn out fatally when stressed by the male when not breeding and defending the fry against stupid catfish that don't get her warning display and pass the territory without a second thought.
If you have a display tank and only a single male Apistogramma you can add Corydoras, though.
Otocinclus are not bottomdwellers, though. They sit wherever they find food. Also not a fish for a freshly setup tank. I'd add them only after the tank is well seasoned and running for more than 6 months.
Anything else like loaches or nocturnal L-Number catfish is probably a bad idea they stress dwarf cichlids no matter what.