^ not entirely true. I havent ever had a tire track or fire eel successfully eat a small fish. I had a 2' long fire eel (in the same family as a TT), and It never bothered catching any rosies or shrimp i would from time to time put in the tank. Also, He would be fine with some tankmates in a 55.
The ghost knife will need a 75 because they get quite big, even a 75g might eventually be a little tight. Its doable though.
Needlenose- Very predatory, i would recommend the 75 for them too, as in my experience they can ram into the glass of small tanks while catching prey. Also, if kept with small fish, it may eat itself to death.
The puffer may be brackish or fresh... what type is it?
The rest of the fish should be okay, but get rid of the community fish, they dont belong in with the predators.
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