Picked up a nice sized toadstool leather coral from the LFS here I really respect. It's been doing fine, however day before yesterday it sucked its polyps in and has developed the waxy coating I read about that they do just before shedding their skin. I redirected a sump return to give it a cleaning flow. I only know by reading, as opposed to experience, that they do this occasionally and it can last a week or so. Many of the sources I've read also caution about toxicity when they start shedding. I do 25% PWC's weekly (while I'm just getting started). Chemistry is AOK. do I have anything to worry about?