Strange Zoa behavior

[CaptainCooke]

Hi everyone,

I have a thriving little zoa garden going and everyone is happy EXCEPT for my pink diamond zoas.
The polyps are open but they keep getting smaller and smaller. They also keep pushing their mouths up so they kinda look like cones or little mountains. Photos below.
I’m not sure what is going on with these guys or why they would be acting like this when all the other zoas around them are huge, happy and splitting.


Please let me know if you have any suggestions for me!

Thanks

 

[Nigel35]

Can you spot out any pests on the polyps? How are your parameters? If you bought them recently it could just be that their settling in.

 

[CaptainCooke]

Can you spot out any pests on the polyps? How are your parameters? If you bought them recently it could just be that their settling in.

No pest that I can see. Parameters all seem right in line.
Alk 8.5
Ca 438
sg 1.025
Po.03
Mg 1250ish
No3 5

They have been in the tank for about 4 months and have had this behavior since they first opened. They have been getting smaller and smaller since.