You can believe the world if flat if you'd like, that won't change what the growth rate of a pacu is. Ye,s they do grow that fast.
You are feeding it a carnivorous diet. Its a vegetarian. In addition to stunting, its being malnourished.
Keep doing the research. A 125 will be a good environment for the fish for at least the next 6-8 months. You have bought yourself a good window of time. You are going to need a new plan after that though. The pacu will break the 125 if you don't find a new plan.
if you looked up in my other threads it has jumped out and fishy go bye bye. 
every1 thinks i am a liar but i have got everything i wanted for the info so screw it!
