I did alot of typing regarding how much a 55 tank can hold, oversized skimmers, and large water changes being able to "push the issue" in terms of the fine line between healthy tank and tank crash. Then, for whatever reason, I looked into those anthias you have. The min suggested tank for these fish is 125 gallons. This basically says you shouldn't add any more fish. Even compared to my 55, you have more in it than I do (I have 7 with an oversized skimmer). Without a larger tank for the anthias, they will either get stressed out from lack of room and die or begin causing parameter issues from amount of waste produced. Sorry to rain on the parade man.
Saltwater Aquarium Fish for Marine Reef Aquariums: Lyretail Anthias Fish