I know my name isn't Lynden, but if you ask me that fish list for a 50g is both overstocked and a recepie for disaster. Maroon clowns are bigtime bullies and in a small tank like a 50 may end up killing other inhabitants longterm. Also, a mandarin is not suited to a tank this small. Bare minimum of a 75g, prefferably a 90g. Perhaps ditching the maroon clowns and instead having something like a niger triggerfish would be a better option. But I'd listen to lynden on triggers since he's definitely "the man" in that department