clown knife, NOT for most aquariums, only the largest will do.

[BlackGhost]

Red Pacus Grow HUGE I got one when it was like 2 inches and in 2 months it grew to 7 inches and then I learned it was going to get 22 inches and it would not even be able to turn around in my tank. So I sold it to my LFS

 

[YahooFishKeeper]

dude... that post is soooo old. i just got rid of my knife yesterday at a whopping 13 inches!!!!! i would watch out black ghosts get huge too.

 

[Intravenous]

not even close to how big clown knifes grow though

 

[YahooFishKeeper]

i saw one at the store i dropped him off at that was about 2 feet long.