My flame hawkfish died today. I am fifteen and new to this hobby. He was my favorite fish and I was pretty bummed tonight . I don't know what happened to him. He started to turn pale a few days ago, but was still eating. He was an absolute glutton! My dad said he fed the tank this morning and he didn't eat and hardly moved. If had a disease I hope he didn't give it to everyone. His tank mates were two ocellaris clownfish, one royal gramma, one purple firefish, and one striped blenny in a 75 gallon. He was the boss of the tank. I looked at other threads on here and it said it could be internal parasites or low oxygen. I tested my water yesterday and my nitrite and ammonia seemed a little high, but last time I went to my LFS, I tested water and I thought that my ammonia was a little high, but he said I had zero ammonia. I think I am just terrible at testing water. I use a Red Sea test kit and so does the LFS. I read that the flame hawkfish was an easy care level fish, but it may not be, I don't know. I also planned on getting a Midas Blenny, but I read that they are a little bit harder to care for so I may not. I wonder if adding power heads in the future would help as well. He had plenty of rocks to perch on and plenty of food. I fed three times a day. Pellets and Mysis. My dad is going to do a water change tonight but I am at my mother's tonight. He said he would call tomorrow and ask the LFS to order another Flame Hawk, but I may tell him to hold off. The LFS quarantines all of the fish, but I don't know how long and if they treat for disease. They are the only trusted LFS around. The other is Petco, but I have heard horror stories from people who have bought from them. The other LFS only sells freshwater. I do not quarantine any of the fish I get. All of the other fish seemed happy and healthy. The flame hawk was until a day ago. My dad does not want to set up a whole other tank. He also does not want to order from Live Aquaria because he wants to support local business. I trust the LFS,. They get most of their fish from Sustainable Aquatics. My tank was set up in early may and I added the Flame Hawk a month ago. I don't know what to do. I don't want the rest of the tank to go down hill and just ruin the whole experience for me.