it's doesn't matter if you take good care of them when you're gonna give them to the zoo or Aquarium because many zoo and aquarium stop accepting fish from people like you.
Around my area, Dallas world Aquarium have the biggest tank and also have the biggest captive pacu in the world. They has stop taking fish from people that have no clue what they are getting when they buy the fish or just too ignorant to care. Their 200k gallon tank is now pretty crowded with the ridiculous amount of pacu and RTC. The tank don't even look as good as a few years ago due to so many pacu and RTC. They even attack the ducks swimming on top of the tank as part of the amazon exhibit. The RTC swallowed the small ducks that fit their mouth and also ate all the small fish in the tank(peacock pass, niger catfish), the pacus started attack the ducks wen they're hungry.
Zoo and aquarium in the U.S are pretty much full of pacu and RTC in their amazon display now that donate your fish when they get too big is not an option anymore.