I'm sorry for your loss. I just saw this thread, the parameters are important for making an educated guess as to what the issue is and recommending the correct medications to use. If the Ph was 6 I doubt ammonia would have been much of an issue but 6 is pretty low for a Festae although that in of itself shouldn’t cause an issue per se. This should have been posted in the Freshwater Disease and Health Issue section where it might have gotten more visibility. You said you were surprised by the lack of response but you also didn’t post in the correct section where a lot of members interested and experienced in treating fish go to look for threads like this.