Silver Dollars and Pacu compatability

Question
I have had a school of 9 Silver Dollars for the past 7 years, I recently decided to add a red bellied pacu into the mix. At this point they are all about the same size, but obviously the Pacu will outgrow them quickly. What is bothering me is that the silver dollars now stay on one side of the tank and only mix with the pacu at feeding time. I found the Pacu to be slightly aggressive and has nipped some fins on the Silver Dollars. Do you think the Pacu will grow out of this aggressiveness or should I consider returning to my all Silver Dollar Tank? The present tank is 55 US gals, but I am in the planning stages to move up to a 125-150 gal show tank. Thank you for any advice you can render.

Answer
Hi Kenny,
 I can be pretty confident that the pacu will NOT outgrow its aggressiveness, in fact, quite the opposite.  It is likely to become more aggressive as it gets larger.

-- Ron
  rcoleman@cichlidresearch.com
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