Borelli yes - maybe even 3 males. There are several people who keep colony if borelli in smaller aquarium such as @Samala who can probably give you some first hand tips. Here thread is here:Setting up a four foot tank with plenty of caves and bog wood and rocks do you think it possible to keep two males with maybe three to five females..the only other fish in the tank will be a group of dither fish.
Yes both rummy and esp cardinals will go after frys. Pencil fishes seem to be the recommended dither; though I've had luck with ember tetra and kubotai rasbora. People say ember will eat frys - i had luck with ember and a. pucallpaensis though i suppose they might have eaten a few frys after mom stopped protecting them.So maybe one male and three females maybe ok…I do have experience with apistos I thought I may get away with two males in the tank but maybe not.
I have bred them before but all the young were eaten by other fish in the tank.(the tank was a planted tank a bit of a South American community tank)
do You know if cardinal tetras or rummy nose tetras would eat apisto fry.
In my experience the only fry safe tetras are small species like Tucanoichthys. That size category should be ok. But there's no guarantee.You know if cardinal tetras or rummy nose tetras would eat apisto fry.