HELP!!!

  • We are currently upgrading MFK. thanks! -neo
2 tinfoil barbs are chasing each other and 1 barb is chasing the pacu but the barb just wants to touch him not nip the pacu
 
I think 30-40 gallons?
Picture your pacu in 2 years...(picture not mine), even 300G still small for a full grow Pacu and they are grow super fast. There is a story of a staff working in publish aquarium and they said they can see Pacu growing everyday, it's very noticeable grow rate, I myself kept them before and I can see them gain their size less than a week if keep well fed and good water (double its size from 3 inches to 6 inches less than 2 months). You best bet and a right decision is rehome your pacu right away!
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Poor pacus, you knew they get too be a dustbin lid sized fish right? Guessing you either got told by the LFS they get to 12 inch or live in the natural range so you can release them, only a handful of members on here with tanks big enough for pacus and most wouldn't entertain such a common huge greedy fish.
 
Greedy is right. Monstrous size and appetite. Gad, mine would literally eat anything edible every hour. Gluttons
 
What's your plan for the pacu? I have a 3-year old that's 2.5' long and 1.5' tall.

It's hard to say what went wrong in your tank because the barbs indeed can nip and so can the rainbow shark. Pacu can nip too and IME the larger ones do supplement their diet with the fins and barbels of their tank mates if the latter are timid and let them do it.
 
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