New Maroon Clown Won't Eat

[Ielliah]

Once my 30 gallon tank was ready with live rock for 3 weeks I added a maroon clown to start cycling. He's been in the tank for 48 hours now without eating. He likes to swim in the back of the tank behind the rock. I tried feeding him some frozen mysis shrimp today but he was not interested. Does anyone have any suggestions? I will check the water levels tomorrow but I don't think they will have changed much since I checked them 2 days ago.