So about two weeks ago I added some Zoas to my tank. They opened up that night and stayed open for a week. But the last week and a half, they have been closed. The past three days I have done a freshwater dip, a tank water with Kent Marines Lugol's Solution dip, then finally a freshwater with Lugols dip. I also did a 50% water change two days ago. They're still closed, everything else looks great. Any ideas?

Why did u do a 50% WC? Zoas I find need time to get acclicmate to tanks....I had some that didn't up for a week but now looks awesome. Just give them time, assuming ur parameters are good, u don't have anything to worry about. I find keeeping ur water stable is key...doing 50% WC might freak out ur tank.

I had to move my tank across the state, so I emptied half the water. But they were closed before I moved it, so that's not it.

If they're not losing color or disintegrating, should I just let it ride out?

50% WC's are not harmful.. what's your lighting and placement of the zoas in the tank.

The dips will have pissed them off for a while.. leave em be for now.

Did you ask them to open that works for me.
Give them time they sound stressed.

+1 just stress. Just bought some not too long ago here from a member. Shipping was 2 or 3 days (in which it was in 70 degree water in the dark). I figured they'd open in a couple days. Took two weeks. They're just now starting to open. Wait it out. Eventually, if there's still part of it there, they'll come back.

No worries, they're just stressed. Give it some time.


Edit: During this time I was experiencing the same thing. Everything else was doing fine, except the zoas. Finally they opened. Just leave them on a rack or on the sandbed. Give it 2-3 weeks (from right now). I'm sure they'll come back. Go back to a regular WC schedule. If everything else is fine, chances are your water is fine too. Zoas are just stressin.

Lighting consists of the original 50/50 light on the JBJ Picotope, on a 12 hour cycle.

The Zoa's are on the sandbed.

Good to hear, thanks everyone!

So last night I saw one of my crabs sitting on top of my zoa colony which is on a small stone plate on the sand bed. I thought this may be irritating them so I thought I would frag them off and glue it to my LR, hoping the crabs may stay off of them. I googled flow and lighting requirements to figure out where to place them, and ran across a site that said that anemones can excrete a substance which is toxic to zoas. I have a bubble tip anemone in there.

Is this true?

Are they under moderate flow? If not I'd move them there so that they open up more quickly, they slime up after all of the dips and can get infections. What's your salinity, and how are you testing it? Higher salinity will make zoanthids close up as well.

I just cut them off their base and glued them to my LR, now they have moderate flow and more lighting. My water checks out by me and my LFS, and everything else (anemone, dendrophyllia, birds nest, ricordia) looks awesome.

I will try raising my salinity a hair, it's in the "green range" on one of those floating / temperature devices.

I did however spot a bug on them shortly after I glued them. He was about half an inch long and his back looked really segmented. I'm going to try to catch him.

What is your salinity at exactly? 1.027 and up and your zoanthids will be closed, definitely not a good idea to bump it up unless you know where it's at... Also, if you're using a hygrometer those are notoriously inaccurate, do you have access to a refractometer at your LFS?

I'm sorry, I meant decrease my salinity.

My girlfriend has one, I'll borrow hers and get back with you.

Thank you!

Be sure to check the stickies in the ID forum. That could be a zoanthid eating spider.

I didn't see the bug in the ID section, but it's definitely not a zoa eating spider.

I did however realize I have a ton of flat worms, but mine are all green. It says they're harmful, but why?