tang

All, Looking for insight on a newly re-established 200 gallon tank where the fish are almost all hiding in the rock and crustaceans die. Salt was about.23 and now have it up to around .26. Temp 77 degrees. Any ideas appreciated.

Been considering setting up a saltwater tank again after I move in a couple months to a more permanent residence. Thinking a 75 reef, red diana hog, scopas tang, and some beginner corals blue mushrooms, green star polyps, maybe try acropora later on. Obviously no snails, crabs, shrimp, or stars...