Spinoid worms, hydroids, thinning zoas

NotReefsafe · Jan 3, 2023

My zoas look a lot worse than they did when I got them 4 months ago. The spaces between the polyps is growing larger and they are shrinking in size. I have found a few spionid worms and colonial hydroids in the zoas, but I thought these were mostly harmless. I have been removing the worms and hydroids as I see them. What else can I do?

ISpeakForTheSeas · Jan 3, 2023

NotReefsafe said:
My zoas look a lot worse than they did when I got them 4 months ago. The spaces between the polyps is growing larger and they are shrinking in size. I have found a few spionid worms and colonial hydroids in the zoas, but I thought these were mostly harmless. I have been removing the worms and hydroids as I see them. What else can I do?

The spionid worms should be totally harmless, but I've heard that hydroids (possibly depending on species) may sting corals.

That said, I'd suggest posting your parameters and some pics of both the zoas and your setup so that you can get some community help in ruling out other potential causes.