What's wrong with my coral?

[syrah_and_co]

Our tank has been easy and trouble-free for 5 years... two days ago we lost 2 damsels, a wrasse and a shrimp, next day another shrimp and now our coral looks like this during the day (strings coming off it) and shriveled tonight...not sure what is happening but scared for those left in the tank

 

[cloak]

With all those deaths in the tank have you tested your parameters lately? Do you have any other corals in the tank? How do they look?

 

[syrah_and_co]

pH 7.8
Nitrate 50
Phosphate .5

Not looking great either...Still have a Goby, Stripe Damsel, Peppermint Shrimp, and Clown who swimming funny at the surface of the water

 

[dontbuyxenia]

I dont know about your fish but kenya tree coral likes to shrivel up like that before it sheds its mucous coat.