Zoa heads closed? Half are quite healthy though

[Gatling]

Hi guys,

Half of my heads on only one of my zoas are completely shut, no signs of opening. The others that do open are very healthy. Here's a photo:

I feel like some algae is covering them up but it's hard to say. My other zoas are healthy. What should I do?

 

[ndrwater]

Try a turkey baster and give a gentle blast. See if anything comes off. There are several types of Zoa pests. Something is definitely irritating them