Zoa Looks Like it’s Dying

[djm]

Hi All

I’ve had this zoa in my tank for approx 3.5 months now in the same location. It was doing well and within the last week it has started to look like it’s receding. When closed up at night there are gaps in the flesh attached to the frag plug and now the polyps have gone an unusual shape rather than being flat when open the middle is raised up.
Any ideas what is causing it and what can be done? I have another 2 Zoas in the tank which are looking fine.
Parameters are;

salinity 1.025
Nitrate 0.5
Phosphate 0.15
Calcium 460
PH 8.2
Temp 25c

 

[T-J]

Umbrellaing zoas usually indicates lack of light.

 

[Reefing_addiction]

Zoas like dirty water.

I would definitely look up umbrella syndrome in zoas.

I don’t believe lack of light causes it, because zoas will stretch for light

 

[djm]

Umbrellaing zoas usually indicates lack of light.

I have a couple of zoas lower down on my rockwork which are doing ok…. I think, pics of the others below. Do you think moving the zoa could save it?

 

[T-J]

I have a couple of zoas lower down on my rockwork which are doing ok…. I think, pics of the others below. Do you think moving the zoa could save it?

Here's a thread from 2017 discussing this:
https://www.reef2reef.com/threads/why-do-some-of-my-zoas-look-like-umbrellas.281666/

 

[Just John]

You may want to look up nitrate levels for zoas. They like some nitrates in there. 10-ish or even higher, depending on who you ask.

 

[Tired]

Yeah, if you actually have 0.5ppm nitrates, that's probably too low for them.