Yep. When the bass aren’t hitting, I break out the 8 ft light action fly rod. I keep a 5 lb leader around 6 ft long on the fly line which is 50 lb test. Have caught many large fish and pumpkin seed bream that way.
One thing to keep in mind on Pacu is that they are shaped like a blue gill, but thicker. So imagine the fight a 5 pound bluegill could put up with those wide sides. Also, if this was a Black Pacu I think they grow to 50 plus pounds ! I have seen them in aquariums at around 20 pounds, they love grapes and chopped bananas.