go for it! mine is 24". he is my favorite fish. hes in my 75 w/ a picasso trigger. i have a piece of pvc for him, he stays in it alot poking his head in and out. make sure you have a secure tank. they will get out if they can find a way. i think that having alot of good rockwork or pvc helps them stay in your tank, not on your floor. mine eats clams, squid, krill, some brine, and silversides. what other fish are in the tank? a 55 is prefect size for one of these. bo