As John says. I have many small sun coral frags, and I put them in a separate container, float the container in the tank, and put in a liberal amount of phytoplankton and enriched mysis or brine(if they're small polyps) shrimp. Then I just use a syringe (turkey baster would work too) to keep the shrimp and phyto in suspension. Give it some time, they'll come out, and they'll eat tons.