I have a 4" round sting ray that has been in my tank for the passed two months now. I noticed 2 brown spots on his underside yesterday (that are also visible from the top). Today he has six. My water parameters are great. no ammonia or nitrites. PH of 8.2. He is eating mysis shrimp and Krill. The only kicker is the water temp. He lives in a 180 gallon reef tank with other tropical fish so I am keeping the water at 76 degrees. i know i shouldnt go over 72 but I would suffer other loss as well.. right? I dont really know, I have only been doing this for 3 months. Can anyone help me with the Brown spots? I do not want to lose him. Thanks so much