8 month old zoas are not doing well!

[HT]

I have some pink zoas that I've had for over 8 months.  The edge of one of them is starting to turn white and that polyp doesn't open all the way anymore, and it seems to be getting worse.  Any help knowledge about what's going on, and why, would be appreciated.

Thx!

[Mr. Ugly]

Turning white can be a sign of water parameters being off. Check your pH, alkalinity, salinity. Make sure you are keeping up with your water changes.

If the polyp is closed it could be due to a predator or irritant. Lately I've been seeing zoa/coral eating asterinas around. Those are the deformed looking tiny starfish. The coral eating ones have blue and red specks/marks on them.

Zoa eating nudibranchs will also make your zoas close up.

Another thing could be zoa pox. Do you see any white patches or pox marks on your closed up zoas?

Have you changed your lights recently?

Can you tell us about your tank and system and what corals and fish you have in it? Any recent changes?

[HT]

Thanks for the reply.  There hasn't been much change in the tank.  I did change out one of the lights to a 20k (I have a nano 24).  I think I need a water change.  I don't see anything visible that is eating the zoanthids.  They've recently started to open up again.  I believe my frogspawn has been reaching them and stinging them.  Do Euphyllias sting zoanthids? 

[thincat]

They sting anything they can reach except other Euphyllias. I think your problem was more to do with changing bulbs. The Zoa was just getting used to the new light combo.