Corals dying?

[DerekT5]

Hi all, I have bought acans about a month ago, were all doing great and then they closed up for no reason. They then lost their polyps one by one. I can find the polyps on the sand looking like a healthy polyp but not on a skeleton body. Does anybody know why?
Thanks!

 

[Tahoe61]

A good rule for this hobby is that any time you see an issue with corals trouble shoot chemistry first. Typically it's an issue with alkalinity, or just generalized swings in parameters.
If it's not water chemistry then perhaps they are being eaten by live stock.
And lastly lighting.

 

[Zack K]

It sounds like Polyp Bailout. Most of the time this is caused by swings or instability in water chemistry, especially Alkalinity Calcium and Magnesium.
What are your Numbers?
What livestock is in the tank?
How often do you test?

 

[iC0ral]

Are you dosing anything? have you check your Nitrate/phosphate lvl? High levels and also zero levels for both are major problems with corals in general.