Really guys? A fox face can go into a 75 am I right? A 55 that's four feet long and properly aquascaped can provide the same amount of swimming room as a 75g so that renders that argument moot. As far as having a large fish like that in a 55 the only other concern is water quality, what's in the tank now? If there is room to accommodate a fox face in regards to bio load and the proper tank maintenance is done and parameters monitored then it's easily done. I have a fox face LO in my 55 with a pair of clowns and a starry blenny and have no issues at all.