How can I tell if zoanthids are dead?

[barry cuda]

I've got one rock with a couple different colors of zoanthids in my 100g, and the polyps have remained closed for over 10 days now. How would I tell if these were dead instead of merely reacting to something wrong in the tank? The common mat is still attached to the rock and looks intact, and the polyps don't look to my uneducated eye like they're decaying, but they've been retracted for so long that I'm starting to wonder. I haven't changed the lighting, and I've tried moving them to a lower-flow area with no luck. I'm having a small ammo spike right now that is still under investigation, but the first trace of ammonia was detected days after the zoos started staying shut. I'm considering the possibility that I have dead zoos causing the ammonia problem. Anyone got any thoughts?

 

[spsaddict]

they disinegrate when a ph is aimed at them, what is the lighting differece, did they conme from pcs vhos mh? also what wattage, imo if it is a big change from lights that could be problem #1,
with that said mine always opened up after 5 min... i give mine med light and med flow

 

[barry cuda]

They've been in the tank since late May, and only stopped opening in the last couple weeks. They're under 260W of PC but I'm not sure what the LFS has over the tank they came out of.
I did take a turkey baster and give them a pretty vigorous dusting off this morning to check structural integrity, and they held together just fine. So this probably means they're still with us? Now I just have to figure out what's bothering them.

 

[spsaddict]

what type of flow? also have you seen any nidibranchs on them?

 

[barry cuda]

No nudibranchs. I did see a bunch of flatworms coming off the rock in the days after it went into the tank, but I think I got them all out and haven't seen one for at least 2-3 weeks.
The original spot in the tank was a pretty high flow location near the overflow. I've since moved them to a spot I'd describe as medium- to low-flow.