I need a little help if anybody has anything they could add to this. About a month ago i purchased two Oscars. They have both been great until about a week ago, one of the oscars stopped eating and wasn’t swimming much. I finally got him to swim around and eat yesterday but today he succumbed to whatever was ailing him. I check my water params. daily and treat their water as well as a weekly water change. The other oscar has been completely fine, running up to me to eat and genuinely just being a healthy fish. Does anybody have any insight into what may have caused this and how i can prevent it in the future? I treated him with a couple of Fritz medications as well as some Melafix from API. Legitimately confused as to whether it was something i failed to do or if it was just one of those things that happens.