Can i keep a birchir or a tiger oscar on a 20 gallon aquarium even if i have a good filter?

Question

help i really like predatory fish Even if it is alone? i don't have much space to have a large aquarium right now so please help think about it? or any tips or advice. because i like to feed insect or small lizard or rat and other fishes

Answer 1

not in the long run. oscars grow pretty fast, so you would be best off just waiting until you can get a 70g+. a bichir would be fine in a 50. you probably couldn't fit a large carnivorous fish in such a small setup.  

Answer 2

If you want to feed your fish rats you better be looking into a piranha.