I agree some schooling fish that are quick would work good. My GT is in a 55 by himself for now because he is pretty nasty towards anything else. He was in a bigger tank with my sevs but terrorized them, so needless to say he is by himself now.
no, blue acara would get terrorized.
you could try and add 1 male convict and some Schooling fish like giant danios.
How big is the Green Terror?
nice tank background i got the same one for my Green Terror Tank