Might want to post your water parameters as well it is going to be asked for to help diagnose and get them out of it. That being said I have from fruit loops that tend to stay closed for a week then open up. Every time I blow off the rocks or a hermit goes over them they close up.
I did get to see them and they looked similar to how they do now though they were brighter. Also I just checked water parameters and am in shock. I have a ten gallon and for the past few weeks it was doing well by liveaquaria reef parameter standards but now my calcium levels are through the roof, nitrites at .25 ppm. Even a very small amount of ammonia I think though the color was very close to 0 ppm and very few nitrates (how did they go down?!) I had a diatom bloom about two weeks ago too and used phosguard to handle it but now I think they went away more so since my water is so bad.
So what are the numbers?
PO4
NO3
Ca
mg
Salinaity
pH
Alk
I have a tremendously hard time keeping PO4 and NO3 above detectable numbers. I ordered a Yellow Clown Goby so I feed the tank more to try and keep the numbers up. Been trying to keep PO4 at .03-.07 and NO3 around 5-10. My tank is only 4g so was extremely hesitant to add a fish but don’t think I have a choice at this point. Unless I want to dose and would like to try not to. this was my parameters yesterday
Salinity 35ppt
PO4: 0
NO3: 5
pH: 8.1
Alk: 8.7
Ca: 440
Mg: 1440