Often time can be of the greatest essence when there's a tank or polyp related issues. To help expedite a swift and accurate response/answer to a question posted here, it's really important to provide as much information as possible and list all of your parameters including...
1. Temp of tank
2. All parameters including , Alk, PH, Mag etc and even Calcium in my opinion
3. Salinity
4. Is it a frag, colony, new addition, wild caught or not, shipped or pick up?
5. Have you made any changes just prior to or during the issue?
6. List the current/flow, even lighting type when applicable.
7. Additives etc
8. If you have something missing, damaged, altered etc, listing your livestock fish, inverts.
As much info as possible including a possible picture could make the difference with one of the helpful reefers here assisting you with speedy reply. Not being mean at all, but it can really make a difference. The people here really like to help.
Mucho Reef
PS. I remember some time ago, there was a reefer who had a serious issue in his reef tank. It took nearly 5 days to get all the facts from him with back and forth replies, and by that time, it was too late and he lost a lot of polyps. If memory serves me corretly, it was merely a parameter which was way off. This is why as much info as possible with the initial post is so vital as it can make a world of difference.