Keeping just male appistrogramma

[Meroan]

Hi people,
I have 20 gallon long aquarium with very good filtration and heater, fine sand substrate, lots of red moorwood roots and plants (java fern, bolbitis, anubias, pistia...); i also add amtra cattapa extract sometimes, cattapa leaves and alder cones.

Currently tank is stocked with 10 corydoras paleatus and 15 rasbora brigittae, and the tank is doing great.

I would like to add some "main" fish to add character to the tank and I was thinking about appistos.

My worry is that i will introduce unnecessary aggression in tank by doing so, and that my cories and rasbora will be victims, because as I understand if i add for example 1 male and 2,3 female appistos (as internet suggests), when they breed they will become aggresive in egg/fry protecting and fight/fend off/stress unsuspecting cories and rasbora.

Is there a solution to that worry and problem?
Can i just add 2,3 male appistos and bypass their breeding (egg protecting) aggression?
Will 2,3 male appistos fight between eachother or is 20 gallon long with enough plants and wood roots ok to disperse aggression.
Also are there significant differences in aggression between commonly available appistos?

So question is, having all that in mind: What is the best course od action for me to get some appistos (and in what number and sex) in my tank, but to avoid or minimize the chance of ending up with stressed or dead fish in my tank?

Tnx in advance

 

[Mike Wise]

I always recommend all male apistos for community tanks. That being said, your tank already has a lot of bottom-dwelling fish so adding more really depends on how it is decorated. Do a search here on how to design territory boundaries and line of sight in an aquarium. Yes, some apisto species are more aggressive than others. If you do add more than one male I always recommend that they be of similar temperament and are different species with different body shapes and fins. So long as each male can establish a territory and one is not super-dominant then males will display to each other but rarely damage each other.