When i got this fish I asked the guy how big will it get. He put his hands out and showed me, and I said, " About a foot?" And he said yeah. Then when asked if it would be fine in a 55 gallon, he said it was fine. I guess the guy didnt know about the fish really, or he didnt care. I am thinking about exchanging it, but the place is kinda far. But maybe I could grow the fish out and later give it away or sell it. I am unsure, because thats a hard thing to do especially if you are attached to the fish. I only had it for a little while and already like it alot.