When you say "sprinkled" calcium, I am assuming you mean kalk powder. If it is, Calcium Hydroxide (aka Kalkwasser or Kalk) is pretty insoluble in salt water and should never be directly dosed to the tank in powder form. It has a pH of over 11 and can directly effect livestock. Basically, not only can it raise pH, it can rain particles on corals and severely burn delicate tissues. It should always be mixed with Ro/di and slowly dosed or dripped to the tank over many hours.
As far as the corals, I am not sure what the prognosis will be. Given their reaction, I would do a major water change.