zoa's closed

The past few days I have noticed that my zoa's havent been opening up when the lights come on, I cannot tell if something is bugging them, my parameters are:
Ph: 8.3
Alk: 2.4meql
Nitrate:0
Nitrite:0
Ammonia:0
Temp 78.8
Could one of the fish be bugging them?

 

when the polyps close they can accumulate sediment, and when that happens they wont open so the problem just getw worse and worse, try to clow over them with a powerhead

 

i wouldnt worry about it unless they look like they are melting away..sometimes they just dont wanna be open..a fish could be messing with them..i have a lawnmower blenny that will just lay all over my colonies of zoas and acans and clam and they close up and then eventually open back up

its pretty hard to kill zoas..

 

Thanks guy I appreciate the help! ;D

 

If they continue to stay closed, as suggested make sure no detritus is collecting on them. Check at night for nudibranchs, sundial snails, asternia starfish.