Soft Coral, like leathers and button polyps, are generally hardier than fish. In general, Coral filter the water while fish pollute the water. The way I do things, I gradually stock a good amount of soft coral and only a couple fish in new aquariums, until they reach a point of maturity, 3-6 months down the road, where stony coral can be introduced. It's not easy to describe what that aquarium "maturity" actually looks like, it's just kind of a "sixth sense" that I have acquired over many years of doing this.

  Are you using Activated Carbon to clean the toxins from the water that the Sarco left behind as it deteriorated?

  Are you saying there is no other coral in your new tank? 

  Would you like to post a pic of the tank here, to see if I or others here can see any potential problems?

Just asking because I assume you'd like to help your tank continue growing and maturing properly.

Aloha,

Mark  

Patience and not moving too fast to stock a tank is very important in this hobby.

This tank is just about 1-2 months old, right. It's not mature enough to keep many animals. Give it 6 months and more animals will do better. Even then, after the tank is years old, there will be animals that don't last long. That's the nature of keeping these mortal animals in relatively tiny glass boxes, trying to imitate mother nature's immense ocean.