I don't know why I bother posting these informative links, since it seems like you don't take the time to read them. All your answers are there. In your other thread, you talk about low alk and now a snow storm. If you read the articles, you would have learned the precipitation event (snow storm) in your tank was caused by an imbalance in your alk/ca/mag ratio and the carbonates precipitated out of solution and dropped your alk.
A snow storm will not kill anything. Do nothing. Let everything settle (clear up) for a day or 2 then test your alk and bump it back up with baking soda.
What is that Precipitate in My Reef Aquarium?