Common green zoas not opening

[OrangetheClownfish]

I bought a green zoa colony 9 days ago. They were brilliantly opening up quite soon after I first put them in the tank. For some reason, about 3 or 4 days ago, patches of them (all on the same rock) would close, but they'll open back in a few minutes. However I noticed today and yesterday that all of them except a small handful don't open. And those that opened don't open fully. Any help?

 

 

My tank is the 16L Ocean Free nano marine tank, bioloads are 1 ocellaris clownfish, 1 blue leg hermit crab, and the zoa colony.

1 hangon filter in usage. Protein skimmer in the tank set is not in use.

Tank temperature: Usually 28 degress celcius

[Guest]

Test for nutrient, and then fresh water dip and use tooth brush scrub the head in case of algae growth


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[OrangetheClownfish]

20 hours ago, Willy Guccivera Yap said:

Test for nutrient, and then fresh water dip and use tooth brush scrub the head in case of algae growth


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i did a freshwater dip yesterday for about 5 minutes. Seemed to have killed off some small critters on the zoas. But so far they're still not opening up, except for 1 or 2, which also barely open up. As for test for nutrient, I don't have any test kits... oops.