Hi all.
This morning when I turned on the lights of the aquarium I noticed one of my angels was dead. It was my favorite one too so I am pretty bummed. He was fine last night when I went to bed, not acting different or anything. The water parameters are fine. Nothing has changed. I had him for about two months and I never had any problems with him. All the other fish seem healthy and doing okay. What could have happened?

This morning when I turned on the lights of the aquarium I noticed one of my angels was dead. It was my favorite one too so I am pretty bummed. He was fine last night when I went to bed, not acting different or anything. The water parameters are fine. Nothing has changed. I had him for about two months and I never had any problems with him. All the other fish seem healthy and doing okay. What could have happened?