Soft corals (as well as all invert life forms) are greatly affected by Magnesium levels. Magnesium makes available Calcium into a usable form to our livestock. It is critical to calcification. Even those of us with softie coral tanks, the coraline algae sucks it up too so we all want to have a level between 1250 - 1350 ppm. Red Sea Reef Foundation C is a liquid additive that will easily increase your Magnesium level.
Not sure what your Magnesium level is? Be sure to purchase my Red Sea Foundation Pro Test kit & find out!