So I have this 55G tank that I cycled to upgrade my synodontis eupterus (that i mistakenly bought as a cory cat and found out later it was infact an eupterus and needed a bigger tank). Now that I put him in there, I need help on figuring out what to put in with him. He is still relatively small, about 3". I would love to get an Oscar but I know that the Oscar will never fit in the 55G comfortably with the eupterus. I really like the big fish like oscars as I already have a 10G with small fish in it and I would love to have some bigger ones in the 55G. At first I was thinking koi morph angelfish but I really also like the fish like jack dempseys and oscars I just dont know what would fit comfortably with my eupterus as there are so many sites saying different things about tank sizes for the bigger fish.