How long have you had it? Blue linkia are nearly impossible to keep in captivity; most live for a maximum of a couple months. Humans have not learned what we need to do to meet their needs in our tanks.
I have had it for one week. I will post complete water params in the morning. I checked my testing kit and noticed that the reagents are quite old. I do not want to risk "bad" parameter information. The thing is that All of the other corals and fish are doing very well. I have not over-fed or over-manipulated the tank. I am completely dumbfounded by this.
The tank is 2 1/2 years old. I have had the fish and polyps w/o problems. I did notice that the Nitrates were at 10 today. I did a water change. Ammonia 0, Temp 80F, Phosphate 0, Ph 7.8. Could it be the Ph?
The red /blue linkia are best left in the sea. they are beautiful animals that do not survive in aquaria. it is sad that we rape the sea of so many animals just to bring them home to kill them. a lengthy pre buy inquirey would have saved you both the hardship you and the linkia are experiencing