Zoa problem

[lar17]

Afternoon, I’ve had my tank going for around 3 months now and have quite a few corals in and fish.
A zoa coral is doing good except one head which is still open but is a quarter of the size and shrivelled, any ideas what’s wrong ?

 

[SnazzyUrchin792]

How long has it been like this? My palys just randomly do this from time to time. They also often do it when something disturbs them, it could be caused by everything from a fish to a snail to a piece of something in the water.

 

[lar17]

It’s happened today as I’ve been at work, checked the water and nitrates are very high, think maybe too much feeding

 

[SnazzyUrchin792]

How high are nitrates? In fact, getting numbers for all your levels would be good

 

[lar17]

Ph:8.2
Ammonia: 0.25
Nitrite:0
Nitrate:50