1. How old is it?
2. How old is your tank?
3. What are the parameters in your tank - salinity, alkalinity, calcium, phosphate, nitrate, nitrite, ammonia, temperature
4. Did you add anything else to the tank
5. Was the lighting the same as the tank it came from?
6. Did you do anything else to the tank - is other stuff looking 'fine'
Lastly - it does not look 'ok'.