My Miami orchid frag has only been opening its polyps at night.. It gets great extension at night but none during the day. I will post pictures soon..
Samantha had suggested the PH/Alk fluctuations between day and night may be the culprit. Now I'm trying to figure out if I need to lower or raise my Alk so that the coral will be open during the day..
All other sps (about 10) are open during the day but not at night.. weird right?