Hello first post. I set up and cycled my 65 gallon tank a month ago. About 2 weeks ago I added an orange spot Goby and a Keyhole Angel. I have been test the water regularly to make sure there were no spikes and everything has been good. Sunday I went back to the store and had them test the water to be sure. All the parameters were good so I purchased an American Sharpnose Puffer. Went thru the application process without issue. They fed regularly yesterday and the water parameters were just fine. I came home to the angel wedged in a rock today dead. I pulled him out and inspected and didn’t see any parasites He just looked dull in color. All the other fish are fine. Tested water again and nothing was really out of whack. Ammonia was a touch high but I would attribute that to him being dead even then it was only at .2. I’m at a loss as to what might have killed him. Does anyone have any advice for a new guy?