What kind of coral is this? Also what is wrong with my coral?

[Leon Gorani]

Hi so I don’t know if I’m posting in the right forum at all so my bad haha but what is the name of this type of coral I have? I can’t remember at all. It’s the front center one in the image.
I have also been having some problems with this coral. In the morning it is opened up but by the middle of the day and evening it is usually always closed up. I run an AI Prime HD so could the settings of the light but up too high? What is the general amount of each light spectrum that these need to stay open? My parameters have been pretty good but my nitrites have been a little high, so do you think that could be the cause of it saying closed for most of the day? I turned down my light settings so the light is weaker during the day to see if it will stay open. Any help would be appreciated! Thanks.

 

[LIreefguy]

its a duncan coral
if you have prime i doubt the light is too high.
its not happy, why is probably water chemistry

 

[Borgie234]

duncans can also be finicky sometimes how long has he been in the tank? and does he accept food. The best thing you can do is test your water

 

[Auquanut]

My duncans like a moderate light and moderate flow. As far as nitrates go, what is a little high?