Don & Rad,
Thanks for the info...and you are right in that not much is available on the net about these fish. My interest in them is as an alternative to grass carp for weed control. Tilapia in my ponds keep the algae in check but don't have a lot of effect on the pond weed which exploded with the touted fertilization a couple of years ago (that's another story entirely). Even though I no longer fertilize, I've had difficulty getting the pondweed back under control.
Grass carp have their pros and cons...one of the biggest cons is I can't keep them in the pond. In fall and winter here we sometimes get tremendous rains of many inches at a time which causes a significant outflow of water over the spillways. In spite of make-shift barriers, most of the grass carp have found a way to escape (to their death) at these times. Also, the carp that have not escaped have become Jabba-the-hut impersonators and don't seem to do much at all. The young ones really get after the weeds for a time.
I'm not interested in chemicals...it was chemicals, i.e. fertilizer that caused this mess to start with. Hence my interest in Pacus. It seems there may be a ready supply of them in the same manner that you got your first ones...i.e. they quickly outgrow all aquariums and their owners, with a guilty conscious, feel an obligation to find them new homes.
I'm continuing to research, but if I don't find anything more negative on Pacus than I've seen so far, there will be a new vegetarian (s) in my ponds.
Thanks for your inputs and interest.