Hi everyone. I have a 6 cm purple tang for 8 months. It was very good and eat everything . But suddenly about 10 days ago it start hiding behind of my live rock for 4 or 5 days. When it came out it's look like it was fine and swim slowly. But after a 2 days I noticed it can't find food because can't see the food and also live rocks or glass of aquarium and swim until impact with them. Now after 4 days it start spinning and its eyes moving fast . I put it in my ref for reducing stress .I posted a video to see it's behavior. Can anyone help me please?