Do you plan to keep any other fish in there? With the proper filtration-- a bit more than you described-- I think you can keep some other smaller fish for variety.
Pacus are not typically territorial, so he shouldn't mind a few smaller tankmates as long as the water is good quality. In fact, i reccomend a few other fish in the tank to make him less likely to have a pacu "panic attack," which can result in injury to the fish's nose (as a result of smashing into the side of the tank at high speed

) or a cracked tank!
I love Pacus! Good luck