I have a lot of Zoe's in my frag tank on plugs sitting on eggcrate. I noticed a few months ago that my Zoe's were not doing as well as they had been. My zoes had all been fully open and growing like crazy. Many had started to disappear and I lost whole frags. My LPS was not affected by whatever this was . I started looking for all the reasons this was happening. Water parameters, temp, salt, lighting, pests, other corals stinging them. I was coming up empty until I took one of the plugs out and dipped it in Coral RX just to see if I could find anything. To my horror many small red flatworm fell off the Zoe plug. I then put on my reading glasses and looking in the water using a magnifiying glass I could see many flat worms on all the zoe polyps and all over the egg crate. These worms had just looked like little specks of algae. They were not moving at all so that made it hard to tell what they were. I put all my frags of zoes in a dip of Coral RX and took the egg crate racks out and hosed them off. I also went to my local FS and pick up two wrasss for the frag tank. Two days later and 90 percent of my zoes are open and happy again . I am so relieved to have finally found the problem. I will have to keep on top of the flatworms and will probably have to dip at least once a week to get rid of all of them but at least I know I can fix it now.