Up until recently, I had a grossly overstocked 55. It consisted of a banded leporinus, convict, Jack Dempsey, raphael cat, and dither fish. In the past was also a blood parrot and severum which I had to remove for aggression issues. I would never recommend this setup to anyone in a million years. The problem with large fish in a small tank is that anyone can tell they don’t belong there. It becomes more sad and messy than impressive.
I have since moved them to a 125 and the difference is night and day. They are all far more active and far less aggressive (once initial territorial disputes were settled) than before.
If I could have done my 55 differently, I would have done a pair of convicts (or similar sized cichlids) and dither fish as well as a catfish of sorts (likely a raphael or bristlenose). A big male convict is a very impressive fish and even gives some of the big bruisers a run for their money. The white ones look a lot like mini amphilophus cichlids (red devil, Midas, etc.).
If you want something more monstrous, look into exodon tetras. They are a small fish (3 inches), but live up to the piranha name more than any pygocentrus. A large shoal is perfect for a 55.
I would also suggest a red wolf fish. They are the smallest wolf fish, but still get a good size (10 inches). They are incredibly active and a great show fish, as well as highly aggressive. One of the most rewarding fish I have ever kept. There isn’t much by way of tankmates that isn’t also a snack, but in a 55 it could possibly be kept with an armored catfish. Mine is in a 36 bow front - as he grows he may need more space but at 6-7 inches now he isn’t showing signs of needing an upgrade.
A senegal bichir is also a good fish for that size tank - it isn’t large enough to prey on other larger fish but is an impressive fish on its own. Delhezi get larger but are said to be good in a 55 (I personally wouldn’t do less than 75 for the extra width). A sen would do well with the African butterflyfish I mentioned in your first thread (which is a relative to silver arowana).
Personal preference, but any of these fish to me are far more appealing than a silver arowana (maybe because aros are overdone).
I have since moved them to a 125 and the difference is night and day. They are all far more active and far less aggressive (once initial territorial disputes were settled) than before.
If I could have done my 55 differently, I would have done a pair of convicts (or similar sized cichlids) and dither fish as well as a catfish of sorts (likely a raphael or bristlenose). A big male convict is a very impressive fish and even gives some of the big bruisers a run for their money. The white ones look a lot like mini amphilophus cichlids (red devil, Midas, etc.).
If you want something more monstrous, look into exodon tetras. They are a small fish (3 inches), but live up to the piranha name more than any pygocentrus. A large shoal is perfect for a 55.
I would also suggest a red wolf fish. They are the smallest wolf fish, but still get a good size (10 inches). They are incredibly active and a great show fish, as well as highly aggressive. One of the most rewarding fish I have ever kept. There isn’t much by way of tankmates that isn’t also a snack, but in a 55 it could possibly be kept with an armored catfish. Mine is in a 36 bow front - as he grows he may need more space but at 6-7 inches now he isn’t showing signs of needing an upgrade.
A senegal bichir is also a good fish for that size tank - it isn’t large enough to prey on other larger fish but is an impressive fish on its own. Delhezi get larger but are said to be good in a 55 (I personally wouldn’t do less than 75 for the extra width). A sen would do well with the African butterflyfish I mentioned in your first thread (which is a relative to silver arowana).
Personal preference, but any of these fish to me are far more appealing than a silver arowana (maybe because aros are overdone).
By the way, to clarify, I'm scrapping both of my original two ideas that started these threads. So 
