Jer4916 is giving inaccurate advise. The fish you listed will be fine while small in a 55, but saltwater fish do not grow to their environment and cannot be dwarfed by underfeeding. A few months of happy living doesn't mean anything as fish won't noticably grow much in so short a time frame. A trigger, puffer, eel, and cowfish all need bigger than 55 at their full size. True, they can take years to reach their full size, but all of the fish you listed get a foot long or bigger. 4 of those in a 55 at full size is just plain silly. They will not be happy fish and will likely die.
Jer4916, your fish must all be small, considering the ones you listed. As long as they are still alive, your slow feeding will not stunt their growth. I don't know what kind of lion fish or angels you have, hopefully they are dwarfs (not to be mistaken with forcefully dwarfing).